Had garmins for years and love 'em. Very easy to use one handed at speed to get to the info quickly with least hassle.
Mapsource marine cartography is a top program and I've had no problems with it navigation or error wise. In fact as a sad tw@t I actually sit and play with the mapping software quite a bit routing ficticious journeys!
Can't say the same about the car road mapping software though.......they seem to have missed three of my roads out on the way to southern france!