The front edge also features a cluster of switches and buttons. A hardware wireless switch on the front activates Bluetooth and Wi-Fi, and a full set of media buttons control audio playback. Unfortunately, the rightmost of these is an eject button, which can be pressed accidentally by a protruding belly. The media buttons also control the Instant On feature, which lets you play music and video without booting up.

Upgrade options aren’t usually a consideration with ultraportable laptops, but the TZ36 nonetheless offers an ExpressCard/34 slot, as well as two USB ports and a mini-FireWire port. There are Memory Stick and SD card slots, too, so it has roughly five times the number of options provided by the MacBook Air.

While the TZ36 is comfortable to use, extremely portable and has an unrivalled battery life – a stunning eight hours under light use, almost four hours if the CPU is pushed to 100% – there’s a trade-off when it comes to power. It feels nippy and apps load without delay, but the 1.2GHz ultra-low-voltage U7600 processor didn’t break any records in our 2D benchmarks. It scored 0.62, which is lower than both the X300’s 0.68 and the Air’s 0.69.

So, has Sony done enough to defend against the newcomers? The laptop is impressive, representing a slight but welcome update to the TZ18. It may be thicker and slightly heavier than the razor-thin Air (web ID: 105978), but it offers a host of useful ports and an optical drive, which Apple has sacrificed. The TZ36 also beats Apple’s sub-four-hour battery life twice over and is equally portable and stylish, albeit for some $500 more.

However, it’s harder to justify the VAIO over Lenovo’s X300 (web ID: 108025). The VAIO has a larger hard disk and greater battery life (the X300 only offers six hours), while the Lenovo’s $4000 price puts it in another bracket entirely. But the X300 serves equally well as a desktop replacement or mobile device, something the TZ36 is far too small to do.

Nevertheless, the VAIO TZ36 occupies a happy medium between the Air’s bare minimalism and the Lenovo’s usability, while easily winning on battery life and value for money – as long as you also have access to a desktop PC for more intensive tasks.