“If (the Eee PC from) Asus starts to do well, we are all in trouble. That’s just a race to the bottom.”

– Mike Abary, senior vice president of Sony’s IT product division, February, 2008

If the netbook market is a race to the bottom, then Sony is bringing up the rear. Not a year after Sony execs disparaged netbooks as undeserving of its premium brand attention, the company announced its token entry into the market: the Vaio W.

Outfitted with a 10-inch screen, an Intel (INTC) Atom processor, 1GB of memory, a 160GB hard disk drive and Windows XP, the machine prices out at $630 in Japan, $499 in the U.S. That’s quite a bit more expensive than rival netbooks. Which is odd since the market for these machines is fairly price-sensitive. Still, Sony (SNE) feels the W is good value for the money, given its design, cheery color palette (white, brown, pink!) and screen resolution–at 1366 by 768 pixels, the W’s display is clearly better than that of its rivals.

Said Vaio chief Nicolas Barendson, “We believe that this screen resolution and design offers our customers a better experience, and that it will be popular with both newcomers to the netbook market looking for a quality portable PC at a netbook price point, and customers wanting to improve their existing netbook experience to date by upgrading their screens.”

Sony’s announcement leaves Apple (AAPL) as the lone major computer manufacturer without a netbook offering, a designation it’s likely to keep for the foreseeable future, according to company execs. “When I look at netbooks, I see cramped keyboards, terrible software, junky hardware, very small screens,” COO Tim Cook said back in April, noting that it’s “a stretch” to call a netbook a personal computer. “It’s just not a good consumer experience and not something we would put the Mac brand on…it’s not a space as it exists today that we are interested in, nor do we believe that customers in the long term would be interested in. It’s a segment we would choose not to play in.”

I’ve been testing one of these new IdeaPads, a small, thin model called the U110, that’s sized to be ideal for travelers. It looks nothing like a classic black ThinkPad. It even comes in red, has swirls etched into its case, and can supposedly log you in by recognizing your face using its built-in camera.

At the same time, I’ve been trying out another similarly sized little laptop, the U2E from Asus (23571.TWO), a Taiwan-based company whose products are relatively new to the U.S. This computer has its own distinctive design: It’s clad in real leather. It also has a camera, and it can be ordered with one of the new solid-state drives, which have no moving parts, instead of a hard disk.

Both of these small laptops are subnotebooks, meaning they weigh 3 pounds or less. Like many subnotebooks, they have small 11-inch screens and somewhat cramped keyboards. And, like most subnotebooks, they are costly — an $1,899 starting price for the Lenovo and $1,999 for the Asus.

Each can only be ordered with Microsoft’s (MSFT) Windows Vista operating system, which means you can practically walk your dog in the time it takes them to start up. Each has a standard battery so wimpy that it provides poor battery life, so both companies throw in bigger batteries that provide decent power, but make the computers larger and heavier.

I wish I could recommend a clear winner between these two contenders, but both are mixed bags. The IdeaPad is lighter, thinner, and has a slightly faster processor. The Asus has a built-in DVD drive, while the Lenovo’s is external. The Asus also has the new, faster “N” type of Wi-Fi networking, while the IdeaPad is stuck with the older, slower “G” type.

Lenovo’s small, thin IdeaPad model called the U110.

The IdeaPad has two big flaws, in my view. First, it has blown the biggest advantage of its sibling, the ThinkPad: a great keyboard. The IdeaPad keyboard has huge, flat keys with slick, shiny surfaces and almost no space between them. I found typing difficult with this setup. I asked two people who are faster typists than I am to try it: One liked it, one hated it. The IdeaPad also dispenses with the TrackPoint, the little pointing stick for moving the cursor that many ThinkPad lovers revere.

By contrast, the Asus U2E keyboard, while nothing to write home about, is more conventional and more usable, with traditional tapered keycaps that provide better key separation. The mouse buttons underneath the touch pad on the Asus, while thin, were sturdier than the ones on the IdeaPad, which had a cheap feel to me.

The second big flaw in the IdeaPad is its most hype-worthy feature: face recognition, which is meant to spare you the need to type in a password to log in. In a dozen tests, it recognized me only twice. I asked my wife to try it, and it never once recognized her. It did recognize a colleague successfully, but we tried it only once with her.

The Asus’s biggest flaw is its solid-state drive. It adds $700 to the price, for a total of $2,699, but is only 32 gigabytes in size, tiny by today’s standards. To compensate, Asus throws in an external hard disk, but that’s an inconvenient solution.

You can order the Asus with a standard 120-gigabyte internal hard disk for the $1,999 price, but that’s still $100 more than Lenovo charges for the IdeaPad with the same sized drive.

Each machine has three USB ports, a video-out connector, a slot for camera memory cards, and an ExpressCard slot, typically used for cellphone modems. Neither has a built-in cellphone data modem. The Asus has three gigabytes of memory, the Lenovo just two.

In my tough battery tests, where I turn off all power-saving features, turn on the Wi-Fi, and keep music playing constantly, the Asus got about 1.5 hours and the Lenovo a miserable one hour and three minutes. This means that, even with a more normal usage pattern, you’d be lucky to get two hours out of the IdeaPad and 2.5 hours from the Asus.

With the included bigger batteries, the IdeaPad clocked out at three hours and 10 minutes, which means you could probably stretch it to over four hours with more normal use. The Asus’s bigger battery delivered an excellent five hours and 29 minutes in my test, which points to nearly seven hours in more normal use. Asus says it has tweaked its machines to improve battery life somewhat.

However, while the jumbo battery on the IdeaPad barely protrudes from the machine, and keeps the weight under three pounds, the one on the Asus U2E is so huge it looks like a tumor and pushes the weight to 3.4 pounds, well above the subnotebook cutoff.

If you’re a frequent traveler, both of these models are worth considering, but each has its own flaws.

• Find all of Walt Mossberg’s columns and videos online, free, at the All Things Digital Web site, walt.allthingsd.com. Email him at mossberg@wsj.com.

But this isn’t the much-touted Apple MacBook Air, introduced last month with all those qualities. Instead, it’s a new ThinkPad from Lenovo, the X300. While the two machines are both impressive products, they are different in key respects.

I’ve been testing the ThinkPad X300 and I have found it to be a solid, innovative laptop that will be perfect for many mobile PC users. It isn’t as sexy or inexpensive as the MacBook Air, but it has numerous features the Apple lacks, especially a wide array of ports and connectivity options, a built-in DVD drive and a removable battery.

I can recommend the X300 for road warriors without hesitation, provided they can live with its two biggest downsides: a relatively paltry file-storage capacity and a hefty price tag. This ThinkPad starts at $2,476 for a stripped-down model and at $2,799 for a preconfigured retail version with a half-size battery. The configuration I expect to be the most popular, with a full-size battery and DVD drive, is about $3,000.

The key factor in both of these downsides is the solid-state drive, or SSD, which replaces the hard disk. The SSD is fast and rugged, but today it can hold only a cramped 64 gigabytes of files and is very costly. Apple offers a MacBook Air version with the same solid-state drive for a similar high price. But Apple also has a much more affordable $1,799 model with an 80-gigabyte standard hard disk. Lenovo doesn’t.

Lenovo’s ThinkPad X300

The X300, due to go on sale next week at lenovo.com and at a few retailers, isn’t as thin as the MacBook Air. In fact, at its thinnest point it is almost as thick as the Apple is at its thickest point. And when the new ThinkPad is ordered in what are likely to be its most common configurations, it is heavier than the three-pound Apple and, in fact, fails to make the three-pound cutoff that typically denotes a “subnotebook.” Only one configuration breaks that barrier, at 2.93 pounds, and it is the stripped-down model with just a half-size battery and no DVD drive.

But the X300, which will come with either Windows Vista or Windows XP, is still very thin and light. It’s under an inch thick and even at its heaviest is only 3.5 pounds. Yet, like the Apple, it packs in a widescreen 13.3-inch display and a full-width keyboard.

Plus, Lenovo has used that extra thickness to good advantage. While the MacBook Air’s extreme thinness makes it gorgeous, it left no room for an Ethernet jack, a removable battery, a built-in DVD drive or a cellphone modem. The X300 has all these things, either standard or as options, plus three USB ports, compared with just one for the Apple. The Lenovo even offers GPS location-finding, the ability to connect to new wireless USB devices and future support for a forthcoming wireless network standard called WiMax.

The ThinkPad has another advantage: Even though its screen is the same size as the Apple’s, it is higher resolution, so more material can be seen without scrolling. Some people find that higher-resolution screens make text too small to read easily, but I didn’t experience any such problem on the X300.

In my tests, the X300 performed very well, even though it has a relatively slow processor, slower than the MacBook’s.

But the ThinkPad’s battery life was only fair, and was inferior to the Apple’s. In my tough test, where I turn off all power-saving features, set the screen to maximum brightness, turn on Wi-Fi and run a repeating play list of music, the X300 lasted three hours and five minutes. That was 24 minutes less than the comparable MacBook Air. And this was on the $3,000 configuration with a full-size battery and a DVD drive. The more basic models, with a half-size battery, would last only half as long, according to Lenovo.

MacBook Air

In more normal use, the model I tested would likely last under four hours on a charge, and the base models maybe two, compared with about 4.5 hours for the Mac.

I also tested another version of the ThinkPad, which substitutes a second, half-size battery for the DVD drive. It got five hours and 15 minutes, which means you could likely get 6.5 to seven hours in normal usage. That model costs around $2,850.

There are two more factors worth mentioning. I believe that both the Mac operating system and the software that comes with it are superior to the Windows operating system and built-in software offered on the ThinkPad. And the Mac isn’t susceptible to the vast majority of viruses and spyware, and doesn’t require third-party security software.

Also, the ThinkPad’s screen, when opened, stands significantly higher than the Mac’s, so it is less usable in a coach seat on an airplane when the person in front of you reclines.

If you’re happy with Windows, can afford the price tag, and value the many ports and connectivity options Lenovo has packed in, the thin and rugged X300 is a great choice. It’s a notable engineering accomplishment.

Email me at mossberg@wsj.com. Find all my columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.

Hard-disk drives, or HDDs, are mechanical devices. They work by recording data on a spinning magnetic platter or platters. By contrast, solid-state drives are made of chips and have no moving parts. They are close cousins to the so-called flash memory used in digital cameras, cellphones and smaller-capacity music players. They record data to special memory chips that retain their contents even when the device is turned off.

Solid-state drives have some key advantages. Because they lack moving parts, they are faster, draw less power, are harder to damage and are quieter than hard drives. Unfortunately, today’s early versions of SSDs for laptops also have two big drawbacks when compared with hard drives: They offer much lower capacity and have much higher prices.

For instance, on the newly announced Apple MacBook Air ultrathin laptop, the HDD version costs $1,799 and stores 80 gigabytes. The SSD version costs $2,798, but actually stores less — just 64 gigabytes. On the Toshiba Portege R500 subnotebook, the basic hard-drive version costs $1,999 and stores 120 gigabytes. The cheapest SSD version is $2,699 and also stores just 64 gigabytes.

Despite these limitations, I believe SSDs are likely to become more common and more popular as their capacities increase and their prices drop. Samsung, which makes the 64-gigabyte SSDs in both the Apple and the Toshiba, has already announced an SSD with twice the capacity that costs much less per gigabyte of storage.

I’ve been testing the SSD models of the Portege R500 and the MacBook Air to see how they measure up to their HDD counterparts. My verdict is that the SSD does deliver on its promises, but, in some cases, just barely.

For the small slice of users who are deeply and constantly worried about hard-disk failures, it may be worth it to pay a huge premium today for an SSD that stores less. Because SSDs aren’t subject to mechanical failures, your data are probably safer on them. But for mainstream users, my conclusion is that it’s too early to take the plunge on SSDs, and the best strategy is to wait for prices to drop sharply and for capacity to rise.

In my tests, I focused solely on comparing the hard-drive and SSD models of each machine, which I had had already reviewed in earlier columns. On the same computer, I wondered, would the SSD make a significant difference in speed and in battery life?

To measure battery life, I conducted my usual harsh test, where I turn off all power-saving software, set screen brightness to maximum, turn on the Wi-Fi and play an endless loop of music.

In this test, the SSD made little difference in the MacBook Air and, in fairness, Apple is making no claims of any significant battery-life gains on its SSD model. The SSD MacBook gave me just five more minutes of battery life. Apple says this is because its hard-drive model already uses a very low-power drive.

On the Portege R500, my first battery test with the SSD model actually yielded significantly less battery life than the hard-drive model. The reason: Toshiba ships the base SSD model with a battery with only half of the capacity of the hard-drive model.

When I swapped in the normal battery, which costs $117 extra, the SSD model gave me an added 1 hour and 21 minutes of battery life, about a 36% increase. That extra battery life likely would translate to nearly 2½ hours in more normal usage. It may be worth the huge price premium for some folks.

On both computers, the SSD was faster than the HDD models. The SSD version of the Apple booted up from a cold start, and rebooted with several programs running, about 40% faster. But the gain isn’t as impressive as it seems because even the hard-drive versions of the MacBook Air booted up in under a minute and rebooted in just a little over a minute.

On the Toshiba, which was running Windows XP, the SSD model knocked about 40 seconds off a cold boot time on the HDD version of 2 minutes and 7 seconds. On my reboot test, starting with several programs running, the SSD model was 80 seconds faster. I imagine that on laptops with the slow-booting Windows Vista, the improvements might be more meaningful.

I also tested launching Microsoft Word and Excel, and opening a couple of hefty PDF files on both machines. The SSD versions were faster. But in most cases, the gains were just a few seconds or even fractions of a second.

All in all, the SSD is a promising improvement over the hard drive, but now is not the time for most users to buy it.

Email me at mossberg@wsj.com. Find all my columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.