Despite recent rave reviews for its ultraportable convertible tablet, the Portege M200, Toshiba seems to have taken a step backward with its new Portege R400-S4931. It is for the most part a successful--and fashionable-looking--notebook, with good speed for its class. But its screen is too thick and unresponsive to work well as a notepad. Considering that some of its other features could have been better executed as well, recommending the this laptop would be difficult even if it didn't cost a jaw-dropping $3499 (as of April 11, 2007).

A sturdy magnesium-polycarbonate unit, the R400-S4931 weighs a light 3.8 pounds--not including a dual-layer DVD writer, which you have to attach separately as a USB peripheral. The quoted weight also excludes the unit's add-on 4000-milliamp battery, a 1.9-pound bottom slice included in the box and intended to augment the primary 4000-milliamp battery. We needed both batteries to achieve a run time of 5.5 hours from the R400-S4931 in our battery tests. Together, the batteries bump the system's weight up to almost 6 pounds.

These design choices don't especially detract from the R400-S4931 as notebook. It has a big, comfortably slanted keyboard (thanks to the battery slice) and a tremendously bright LED-backlit 12.1-inch screen. Fashionistas will appreciate the eye-popping black and white case. On the other hand, tablet users will find the extra weight a bit onerous, and keeping track of the extra pieces is a hassle.

Like many other wireless-capable notebooks, the R400-S4931 has no modem jack, but it also lacks a next-generation ExpressCard slot and a shared memory card slot. It is fully equipped for wireless communications, however, with integrated Bluetooth, Wi-Fi, and Verizon EvDO cellular broadband. A one-line status LCD on the front of the unit uses wireless networking and Vista's new SideShow capability to keep on-the-go professionals zeroed in on their next appointment. The LCD synchronizes and displays e-mail and calendar notifications and status information such as Wi-Fi activity, battery life, and time, even when the notebook is in suspend mode or completely turned off. Because the LCD remains visible at all times, you can stay in the communications loop with just a quick glance.

For use as a tablet, the R400-S4931's screen easily turns 180 degrees and closes against the keyboard for writing, but there are no visual cues (like the arrow most tablets have) imprinted near the hinge, so you might turn it the wrong way. Tablet buttons are plentiful and easy to customize to make navigating your work in tablet mode easier. Not everything worked smoothly, though. Changing to tablet mode automatically rotates the screen to portrait mode, but changing the orientation after that can be troublesome. We had to press the orientation button beneath the LCD repeatedly while holding and jiggling the unit in its new position; and the picture took several seconds to change.

The screen's glossy, scratch-resistant coating makes the notebook display great, and writing on it in tablet mode was fairly easy once we got used to the extra thickness. But that glossy layer seemed to get in the way of taps. We had to tap hard and sometimes more than once to register choices.

Performance is another weak area for the R400-S4931. Equipped with a 1.2-GHz Core Duo U2500 processor and 2GB of RAM, it posted a fair WorldBench 6 Beta 2 score of 48. Its slow 4200-rpm hard drive probably contributed to its pedestrian performance.

The R400-S4931 is stylish, and its side LED and wireless-focused design may be trailblazing. But too many design inconveniences, along with difficult tablet input, make this model one of Toshiba's rare unsuccessful efforts.

Carla Thornton