I love my GPS Pilot 3 (but they are not sold now). I flightplan using Airnav, then plug the same route into my GPS, then cross check all the distances and headings. I use it as a VFR flight aid, and always follow my position closely on the chart. The GPS is great for spotting diversions from track and for finding that elusive field. In light of my experience when my Pilot 3 croaks I will go for a Garmin 296 without hesitation.
An aviation GPS is useful (over a land based one) as it gives you the CTR steps, navaids, airfields, etc which can be cross checked to charts.