There are three members of the Acer p600 series that the company calls professional navigation devices. The p610 is the basic model at £180, the p630 costs £200 and adds European maps and Bluetooth, while this p660 is at the top of the tree and includes TMC (Traffic Message Channel) and comes at a street price of £239 (inc. VAT).

The receiver unit is very slim and svelte, but that impression is lost by the time you've attached the hefty windscreen mount, plugged in the power cord and connected the TMC aerial, which you are supposed to attach with two tiny suckers and route around the perimeter of the windscreen. It looks a complete mess and to cap it all, the TMC performance was less than ideal.

The receiver has a big, bright and vibrant screen with substantial virtual buttons that are fairly easy to operate with a fingertip, although you also get a stylus in the package.

In some respects, the p660 reminds us of a PDA rather than a dedicated GPS unit, as it took a relatively long time to lock on to the GPS satellites. After that, the screen displayed seven satellites with individual signal meters, with glimpses of three more satellites, like some sort of graphic equaliser.

The other annoyance was that you have to toggle the virtual keyboard between letters and numbers when you want to enter a postcode. Selecting a destination and navigating with the map was fine; however, the POI (Points Of Interest) feature was awful.

To select an airport or garage for example, you have to scroll down a list. After that you can narrow the field by selecting a likely candidate from a list. However, the information given is limited to a phone number, so if you want to find a restaurant in a strange town, you'll find you're on your own.

For all its faults, we still found it a handy device to use.