The NS20M/S is Sony's latest budget laptop and an update to the NS10J/S, which won a Best Buy in Shopper 251.

The main change is the processor, which is a newer Core 2 Duo T6400 rather than a T5800. Both processors run at 2GHz and have the same specifications, except that the T6400 is manufactured using a 45nm process, which should make it cooler and more power efficient.

There's a marginal performance increase in the NS20M/S compared with the older model, and battery life has improved. We recorded a light-usage battery test score of four hours and 45 minutes, which is 45 minutes more than the NS10J/S managed. This makes it good for use on the move, although at 2.9kg you wouldn't want to carry it far. Games are out with this laptop, as the Intel GMA4500HD onboard graphics doesn't cope well with 3D titles.

Apart from the processor, the NS20M/S is essentially the same as its predecessor but with a larger 320GB hard disk. It has Draft-N WiFi, four USB ports, a FireWire port and an ExpressCard/34 slot. Sadly, there are no HDMI, S/PDIF or eSATA ports and no Bluetooth, so it's not the best laptop for those who want to connect peripherals wirelessly or output music or movies to a home entertainment system.

The design hasn't changed, and we liked the textured silver case with its herringbone pattern that looks industrial and makes the laptop easier to grip. The 15.4in widescreen display with its resolution of 1,280x800 is bright, and colours are vibrant and more accurate than on other models here. The keyboard is firm, although we're not too keen on the flat-topped keys as they have less tactile feedback. The touchpad is large and sensitive, with large buttons that have a light action.

There's nothing particularly wrong with the NS20M/S, although it's not a big improvement over the previous model. Its biggest problem is that Acer has done such an amazing job with the 6530G that the Vaio just can't compete. Unless you need the long battery life, Acer's laptop is a better - and cheaper - choice.