Lengthy battery life, limited specs and a light chassis characterise the average netbook. But PC Advisor finds that not all fit the mould, in our round-up of eight top models.

If you're looking to buy a netbook, the chances are that you're either attracted by the compact, carry-anywhere form factor or the enticingly low price compared to a full-size laptop. While mini laptops tick both those boxes, it's important to remember that they are a compromise in performance and usability compared to laptops with 13in or larger screens.

Screen size is the first restriction. This is necessarily limited in order to make a laptop small enough to slip into a satchel or handbag. The first popular netbook, the Asus Eee PC 701, had a screen measuring just 7in diagonally. Later Eee PCs saw 9in screens fitted; now 10in has become the standard, giving a more comfortable view of your desktop.

Another useful consequence of the move to 10in models is that it allows netbook manufacturers to address their other big disadvantage: severely cramped keyboards.

Even 9in-screen models sport keyboards that are just too tiny for relaxed typing. Step up to a 10in screen, though, and you'll find the netbook's chassis will stretch to about 25cm across. This allows for a keyboard that's 90 percent or more of the size of a full-size laptop keyboard.

Netbook manufacturers are shy to fit a screen with a resolution greater than 1,024x600, assuming the machine uses an Intel Atom processor. These low-res screens limit the software that can be used on a netbook - many programs demand a minimum resolution of 1,024x768. Even navigation can be an issue as you routinely find the ok or Cancel confirmation button is just below the screen horizon.

There are a few exceptions to this rule, such as a custom-ordered Dell Inspiron Mini 10. Otherwise, if you need more than 1,024x600 we recommend you look out for one of the AMD-powered netbooks that are starting to appear. Medion's E1311 and E1312 are among the first we've got our hands on - look out for a review in the next few weeks at pcadvisor.co.uk/reviews.

Like the full-size laptop sector, the netbook market is dominated by high-gloss screens. Their colour range - with dark blacks and reasonable contrast - is impressive, but they are distractingly reflective when used under office lighting or with your back to a window. This can be a divisive issue of taste, but remember that models such as the MSI Wind U100 and Samsung NC10 are successful matt hold-outs in a shiny-screened world.

NEXT: what to expect, and life on the road >>

Business IT reviews and news