We got the Garmin Nuvi 660 not too long ago and sent it back. At nearly $800 it was mighty expensive. I ended up getting the Garmin / Kenwood G510 and plugged that into my car's flip up LCD instead. It's basically the same interface, though I lose the portability.

I think for a much lower price, I can live with a small screen and fewer bells & whistles. These things change so fast we end up getting a new one every year or so and giving our old ones to relatives.