Another area of weakness, and one that scuppers any ideas of using the FZ31Z on the move, is the poor battery life. In the MobileMark 2007 Productivity test it manages just in excess of two and a quarter hours, with the Reader and DVD tests coming in at two hours and 26 minutes and a very poor one hour and thirty-seven minutes. None of these results compares favourably to what we'd normally expect and without doubt the extra power required for the double lamp backlight has a major part to play here.
Application performance is far more positive. In most tests the FZ31Z performed very well, though as noted previously the slow hard drive means it gets bogged down when dealing with multiple tasks. Our in-house tests also showed that batch image editing and video creation is very fast, so anyone interested in photo editing or video authoring will find this machine more than capable.
But this performance isn't enough to assuage some doubts we have about this particular model. Though the screen is without doubt a good one, the cost in battery life for a 15.4in notebook is little too high for comfort. This puts a significant dent in any advantage it might have over larger 17+ inch notebooks that have a similar multimedia focus but benefit from generally superior audio and larger viewable area.
Alternatively, if it's a 15.4in you really want, you're probably better off looking at the likes of the Dell XPS 1530. This is available with Blu-ray a drive and though its speakers are equally unimpressive, it is arguably more attractive and obviously benefits from the customisation possible with Dell. Moreover, it's also slightly cheaper at £940 inc. VAT for similar components and a larger and faster 320GB 5400rpm hard drive. Plus, with the money saved, you could upgrade to a 1,440 x 900 or even 1,920 x 1,200 resolution display.
On the flip side, there are other notebooks in the FZ range, such as the VGN-FZ38M, which arguably offer a better balance of features and price. Though lacking the high colour display, it won't suffer the battery life gremlins seen here and the lack of faster graphics isn't a huge loss in the greater scheme of things.
Despite initially impressing with smart design and good features, the FZ31Z is let down by poor battery life and appalling integrated speakers. It's still a good machine in many respects, but other 15.4 inchers offer a better balance for less money, while larger notebooks can boast stronger multimedia credentials.