When I reviewed Lenovo's ThinkPad W700 desktop replacement notebook, I described it as taking a kitchen-sink approach to mobile computing, mainly because it has a high-end CPU and workstation graphics, a huge screen, and an integrated drawing tablet. The W700's new sibling, the W700ds, brings another dish into the dining room--a second, slide-out display.

Many people use multiple monitors with their desktops; it's a cheap way of gaining screen real estate (cheaper than simply buying one really big monitor). But the W700ds already has a very large monitor, for a laptop--a 17-inch, 1920-by-1200 resolution model with 400 nits of brightness. The second screen has a diagonal measurement of 10.6 inches, or the same size as the ones found on some small netbooks, but oriented vertically; it has a resolution of 768-by-1280 pixels.

The secondary screen is of the same height as the main screen, but because it is stored in the lid behind the main screen, it rests about half an inch farther away from you; that distance was enough to throw off my perception of it as extra desktop. It felt clunky, for example, to store Photoshop tools on the second screen. The bigger issue is that the second screen's image quality seemed pretty poor to me, with a very narrow angle of view, and the main screen's viewing angle already seemed pretty bad. You'll be viewing the second screen from an angle nearly all the time, too, unless you lean over to the right, as I often did. Despite fiddling with several settings and trying the notebook's built-in Pantone color calibrator, I could not get consistent colors on the main screen or the secondary screen.

The secondary screen doesn't seem all that sturdy, either, and it's stuck out there in a pretty vulnerable spot. It probably goes without saying that polite owners wouldn't be able to use it on an airplane, except perhaps in the first-class section of the cabin. The notebook's lid alone is nearly an inch thick, too--that's thicker than many ultraportable laptops are altogether.

The W700ds we tested came with a 2.53GHz Core 2 Quad Extreme QX9300 processor--a $1000 upgrade from the 2.8-GHz Core 2 Duo T9600 processor in the Thinkpad W700 we tested. The costlier CPU may speed some multicore applications, but it didn't help at all on our PC WorldBench 6 benchmark. The W700ds earned a score of 98, a single point less than the W700 we tested. That's a statistically insignificant difference, but if it were my money, I'd like to see a little more benefit from the costlier CPU. Both systems had 4GB of RAM, two hard drives configured in a RAID array, and nVidia Quadro FX3700M workstation graphics; and both ran on Windows Vista Business 64-bit.

As with the W700, the W700ds performed well on game tests, running Far Cry at 1280-by-1024 resolution with antialiasing enabled at 187 frames per second. But the W700 ran the same test at 219 fps--an odd discrepancy, given that we conducted all of our tests of the W700ds with the second screen stowed. We can only attribute the difference to the faster clock speed of the CPU in the W700.

The battery in the W700ds lasted about 3 hours, which was the same length of time as the W700--as long as we had the secondary screen stowed. When we ran our battery test on the notebook with the screen activated, the battery life dropped by half, to only 1 hour and 46 minutes--another reason to keep the second screen off on long airplane flights.

The W700 is the second laptop to incorporate a drawing tablet (the W700 was the first, of course), and it's a neat addition to the notebook; if you're going to buy a humongous portable, you might as well do something productive with all that space. The digitizer pen stows in a spring-loaded slot on the right side, and it's pressure-sensitive, so you can use it with sensitivity-aware applications like Photoshop and Corel Painter, and with Windows Tablet PC input.

The notebook, as with most Thinkpads, provides an excellent keyboard, with big keys that have lots of travel, and a separate number pad. It has an eraserhead pointing device and a trackpad; unfortunately, you can use the drawing tablet for mouse inputs only if you use the pen.

The second screen doesn't add much functionality, and it consumes an inordinate amount of battery life. It's a pretty big waste of money, too--it adds $420 to the cost of an otherwise-comparable W700. For that money, you could buy a 24-inch desktop display, connect it to a W700, and enjoy a desktop that stretches from here to Sunday. The W700 is a well-designed desktop replacement notebook; the W700ds adds nothing that I couldn't get in another, better form, for less money.

--Alan Stafford