I have used a Garmin 296 since they first came out and a 196 before that. Just taken delivery of a 496 and am impressed with that. Just about to write a few lines on it for flyer. The Garmin kit is first class, the 296 has over 10hrs battery life and superb display. I power mine from the aircraft but use the standard ariel and have only had a couple of lost sat instances in over a 1000hrs of use. I use it as a backup to my GNS430 which is my primary nav source (dont bother with all that old DR tosh).
I hope the 496 delivers in the same way.