I have a Garmin 350 Nuvi. It has a lot more features than I would probably ever use. I really enjoy it most of the time. I have found that if you travel where there is a lot of highway construction, and recent changes then it really gets screwed up. That little lady inside will say "recalculating" in a little less than happy sounding voice, and try to help you find your way out. Course if the exit is now a right exit, and you are prepared to exit left, it can be a real pain.
You can pay an ongoing extra fee to get traffic updates etc.
I'm glad to have one, and most times it is very helpful. I can always hit take me home, and it will get me back there. What else could you want?