I use the Lowrance 1000 - the b/w version. It's great but you have to buy the additional mapping for the UK to really get the most out of it (the aviation database is fine but the basemap is too... basic). It's also larger, physically, than I expected, but it does come with a great selection of mounts (yoke, suction, &c).
The software has some limitations - there are no non-ICAO airfields, and if you add your own they can only be 'waypoints' i.e. don't benefit from any of the things you can do to airfields. And MATZs are not shown, but I don't think that's unique to Lowrance!
Unlike the Garmin units it doesn't do 'proper' road navigation, though it works just fine with the additional UK map, even showing which side of the road you are driving on!
Tim