Despite recent rave reviews for its ultraportable convertible tablet, the Portege M200, Toshiba seems to have taken a step backward with its new Toshiba Portege R400-S4931. Here's our first review of the Toshiba Portege R400-S4931, which is not yet available in the UK.

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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 $3,499 in the US.

A sturdy magnesium-polycarbonate unit, the R400-S4931 weighs a light 3.8lbs - 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 1.9lbs 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 6lbs.

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 12.1in 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.