If you're considering a Panasonic Toughbook, it's likely that your priorities are relatively different from that of the average consumer. Rugged laptops are designed to meet the adverse conditions that people in the military, construction, and various outdoor professions may face—and come through unscathed. That said, a laptop still needs to have some basic elements in order to ensure a decent user experience. Although the Panasonic CF-U1 ($2,500 street) has some neat features—like hot-swappable twin batteries and options for GPS, 3G mobile broadband, and extensions like fingerprint readers and bar code scanners—its basic usability is lacking. The CF-U1's screen is tiny, its keyboard is nearly impossible to type on, and the labsence of any sort of navigational aid (like a touchpad or pointing stick) for its otherwise finicky screen make this pricey tablet extremely difficult to use, let alone recommend.

The CF-U1 is nothing if not compact. It's a slate tablet, and it measures only 2.2 by 7.2 by 5.9 inches (HWD). It comes with an attached strap and can easily be supported in the palm of your hand. It also weighs a mere 2.3 pounds, less than all but the tiniest systems we've looked at. Although it's a slate tablet, it's better compared with systems in the netbook category, with which it shares a similar form factor and the Atom platform. The CF-U1 doesn't get any points for aesthetics, but that's not its goal. Being a Toughbook, it's all about the rugged features, like its magnesium-alloy cage chassis, sealed all-weather design, and port covers that snap into place. Though we didn't put it through ruggedness testing, we know that the CF-U1 is tough enough to be considered fully ruggedized since it passed the complete MIL-SPEC testing regimen (developed by the U.S. Military to test the durability of electronic gear under adverse conditions). According to Panasonic, it's resistant to rain, spills, dust, and vibration, and should be able to withstand a 4-foot drop.

The CF-U1 screen's 1,024-by-600 resolution is what you'll find on most netbooks nowadays, though the 5.6-inch screen is tiny by netbook standards. If the resolution were any higher, text would be virtually unreadable. Case in point: the Fujitsu LifeBook U820, which has a 1,280-by-800 resolution on the same-size screen. Though photos, videos, and movies look better on the Fujitsu, text readability suffered. Moreover, the CF-U1's small text presents a unique challenge: The tablet is a touch screen, meaning that when you are clicking links or selecting text, you have a much smaller target to aim for. You have the option to zoom in with a handy toggle switch to the left of the screen, but even then, it's difficult to navigate. And although Panasonic claims that the widescreen has received an anti-reflective treatment, I noticed some glare under direct light. On the bright side, the CF-U1 does boast an efficient LED backlight, which likely contributes to its impressive claimed battery life. (More on that later.)

A tiny keypad is situated beneath the screen. Panasonic made some interesting choices, like including a dedicated Windows key and placing the numeric keypad in the center (between QWERT and Y). The keys are raised, glossy buttons, and you have to press each deliberately before it registers. Forget typing with any sort of speed. Touch typing is out of the question—typing on this is more like thumb-typing on a cell phone. You'll often have to go back and fill in any missing letters if you don't press a key hard enough.

The feature set is par for the course when it comes to handheld PCs. Like the U820, the CF-U1 has only one USB port, which led to an interesting conundrum. For most of my review process, I used an external mouse to navigate. This meant that if I wanted to use any other USB device, like a thumb drive, I was limited to navigating with the touch-screen interface. Dragging and dropping files using the touch-screen interface proved to be far more of a challenge than it should have been. The CF-U1 also offers an SD slot, though it's missing the multicard reader that many of its competitors, like the MSI Wind and the Lenovo IdeaPad S10, feature. Storage space is pretty minimal. The CF-U1's solid-state drive makes sense (it's more likely to withstand impacts), but our review unit had only 16GB of storage space. Panasonic also offers a slightly roomier 32GB option, but even that seems paltry compared with the IdeaPad S10's 160GB, 5,400-rpm spinning hard drive.

The small hard drive was one of the reasons we weren't able to report most of our usual benchmark test results. SYSmark and MobileMark couldn't run because of space constraints, while CineBench R10 was limited by the CF-U1's single-core processor. Our Photoshop test wouldn't work, either, because the screen's resolution was too low. The one score I can report is the U1's Windows Media Encoder time of 6 minutes 25 seconds, nearly 2 minutes behind that of the IdeaPad S10. The lag is attributable mostly to the CF-U1's slower processor. While the other two netbooks we compared it with, the S10 and the MSI Wind, have 1.6-GHz Atom processors, the U1's is only 1.3 GHz.

Though we couldn't run MobileMark on the CF-U1, under anecdotal testing it lasted 4 hours 31 minutes on a DVD rundown test using both of its 21-Wh batteries. The hot-swappable batteries are a plus: You can leave both in the U1 and let it the U1 run on full battery power, or remove one to charge while the system continues to run on juice from the remaining battery. The batteries are easy enough to access, residing behind panels that pop out on the back of the system.

Our review unit ran Windows XP, but you can also opt for Vista when you're configuring the system. I wouldn't recommend this, however, unless you opt for more than the 1GB of RAM our review unit came with.You would need a minimum of 2GB to run Vista properly. The U1's integrated graphics are nothing to brag about, but Toughbook users aren't likely to be too concerned about graphics performance, as that isn't the point of the system.

The Panasonic Toughbook CF-U1 is certainly rugged enough for you to take into any extreme conditions. Still, this slate is frustrating to use at best. The Editors' Choice MSI Wind weighs only slightly more and offers a far better user experience for roughly one-fifth of the CF-U1's price. Then again, aggressively priced systems like the Wind and the Lenovo IdeaPad S10 just don't offer the same rugged features or battery stamina. The question to consider is if it's worth the CF-U1's expense—and its frustrating user experience—to get a tablet PC as tough as it is tiny.

Check out the Panasonic Toughbook CF-U1's performance test results.

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