Sony VAIO VGN-Z31VN/X review

In Speed mode the VAIO lasted just over two hours in our heavy use test and 7hrs 4mins in our light use benchmark. Flick over to the Stamina settings however, and you can turn this laptop from mobile powerhouse to indispensible business tool - we saw the VAIO last for a remarkable 9hrs 10mins in our light use test. The Nearest contenders, from Toshiba and Lenovo, last for six and a half hours: good, but not a patch on the Sony's all-day lifespan.

The VAIO's tiny frame manages to pack in plenty of decent components besides the CPU and pair of graphics chips. A 320GB hard disk is far larger than the 128GB SSD drives offered by Apple and Lenovo's rival ultraportables, but it's a trade-off between capacity and an SSD's speed and reliability. If you're not going to use all the space provided by the Sony, then an SSD model may be a better option in a machine that, inevitably, could take a few knocks.

The Sony matches the ThinkPad X301 for connectivity: both machines are kitted out with draft-n wireless, Bluetooth and an HSDPA modem, ensuring that it's possible to stay connected even without a wireless hotspot in sight, and a TPM module will be a welcome addition for business users.

And versatility is improved by a plentiful selection of connections. Two USB ports, Gigabit Ethernet, a mini-FireWire port and audio and headphone jacks sit alongside VGA and HDMI outputs. It's not quite as impressive as the ThinkPad X301, which packs in an additional USB socket as well as ExpressCard/34 and a DisplayPort socket, but it's a vast improvement on the minimalism of the MacBook Air.

The Sony VAIO Z31VN/X quite simply forces all of its rivals it into submission on most fronts: it has more power, better design and superior battery life to every other ultraportable we've seen. It is a machine almost without compromise and, consequently, should sit proudly atop any mobile worker's laptop shortlist.