Sony VAIO VGN-FZ31Z

Fire up a Blu-ray disc, though, and any qualms about colour accuracy are soon banished. The panel handles motion well and, whilst not 1080p, it still manages to reveal a good amount of detail. It did a particularly great job of differentiating between the tricky dark green and brown shades in our test clip of Harry Potter and the Goblet of Fire.

The upside of using a relatively compact 15.4in screen and chassis is that the Sony remains reasonably portable, and especially when compared against the mammoth bulk of the likes of Acer's Gemstone Blue 8920G. The lack of lid clasps means that we'd hesitate to transport it without a suitably protective laptop bag, but the 2.7kg weight is certainly manageable.

The only fly in the ointment is the Sony's dreadful battery life. You'd hope that the 45nm Penryn processor might improve matters, but even when sitting idle the VGN-FZ31Z failed to last two and half hours. If you were hoping to watch Blu-ray movies on the train, with the extra CPU and graphics power required for the decoding, well, you'll need to purchase an extra battery to make it to the final reel of most films.

The Sony VGN-FZ31Z might be a powerful, well-built laptop, but at £979 it fails to rival its predecessor, the VGN-FZ21S, in the value for money stakes. And around this £1,000 mark, it finds itself up against some pretty stiff competition.

Acer's previously mentioned 8920G, which we previewed last month, is now available from www.laptopsdirect.co.uk for the same price as the Sony, yet it has an 18.4in 1080p screen, a 320GB hard disk and a noticeably better set of speakers. Given that the Sony's poor battery life greatly reduces its portability, we'd have to go for the all-round superiority of the larger Acer.

Author: Sasha Muller