We've been impressed by Sony's VAIO Z-series on a number of occasions, mainly thanks to its amazing blend of power, portability and battery life. The VAIO VGN-Z31ZN/X sits at the top of the range, with high-end components, great connectivity and a comprehensive features list.

The 13.1-inch screen is superb, with a matt finish that's ideal for a life on the road. With LED backlighting, colour reproduction is accurate and bright, making it a great choice for watching movies or even editing photographs. The 1600 x 900-pixel resolution is the crispest available on a screen of this size, providing pin-sharp images, while also offering plenty of space onscreen for multi-tasking.

The provision of both an integrated Intel graphics card and a dedicated Nvidia GeForce 9300M GS chip offers the best compromise between battery life and multimedia power, and it's possible to switch between them on the fly. Using the integrated chip, we managed to get a staggering 478 minutes battery life between charges, yet it's possible to also run even the most demanding multimedia tasks using the dedicated Nvidia GPU.

The 2.66GHz Intel Core 2 Duo processor and 4096MB of memory also result in some of the best benchmark results we've seen to date, even bettering some quad-core gaming machines. The keyboard offers excellent usability, and while the keys aren't the largest we've seen, they feature plenty of space between them, making it easy to type at speed.

Sony vaio z31n/x keyboard

Build quality is among the best we've ever seen, with a mixture of brushed aluminium and magnesium alloy used to create a truly premium product. Combined with the 1.5kg weight, this is a truly fantastic ultraportable machine.

Cutting-edge features

A host of cutting-edge features are in place, including a 128GB SSD (Solid State Drive) and an integrated Blu-ray drive, letting you enjoy the latest high-definition (HD) movie discs. An HDMI port is also in place, enabling connections to external HDTVs. The two USB ports are slightly limited, however, although Bluetooth is provided to connect peripherals wirelessly.

The 3G connection manager offers a simple way of connecting to the internet on the move, and isn't tied to any specific network provider. Sony does make it easy to sign up to a T-Mobile data plan, however. As with the other laptops here, 802.11n Wi-Fi also offers the fastest wireless connection speeds currently possible.

As with previous Z-series laptops, the VAIO VGN-Z31ZN/X has left us deeply impressed. It's everything a laptop should be, in an ultraportable package, with only the high price letting it down.

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