I have an iPaq and bluetooth gps running with memory map and the official CAA charts. It saves having to scan in and calibrate maps which you have to do with some programs. The moving map display is very good but I also have a Garmin Pilot III and a Magellan 315 for general use. The magellans are about 40 quid these days and very good, certainly as good as if not better than the garmin 12. They were until recently issue for RAF aircrew.
Rgds
Rich