I think the unit is great!
I have had no problems with the GPS at all.
I have both City Navigator and the topo maps. I took a 40 mile paddle down the Susquehanna, every major island was on the map, and it tracked me around each island and channel in the river. That impressed me.
I have used it on a commerical jet, it easily got reception when held near the window. It was way cool to know what you were looking at and how fast you were going (540 mph).
The unit is very easy to use. Last week I took a business trip, my coworker never used this particular GPS, he was able to figure out how to find us a place to eat, and find the hotel we were headed to, without me telling him how to do it.
The auto route worked like a champ, finding even new businesses, like the Bass Pro shop in Harrisburg.
I took a short cut coming home, the last 20 miles. The auto route easily adapted to the change in course and directed us back, the way I normally go, which was via some very small back country roads.
I like the expandable memory. This allows me to load one chip with lots of detailed info.
I am heading to Alaska on Frday, I have the topos of interest and all of Alaska on city navigator and most of Canada, so I know where I am when I am flying, and I still have 400 megs of space on my 1 gig chip.
In all, I am quite pleased with this GPS , and would buy it again.
Enjoy!