One of the keys to using GPS is to get the exact address, one little syntax error and ANY GPS will lead you down the merry path. Sometimes that can mean the difference when two cities are adjacent and the streets overlap...which can be frustrating.
I think the Garmins are better, better routes and better maps. I have a Garmin NUVI 760. If I had it to do over I would have got a cheaper one, most of the stuff I don't use. If you have a iphone, you can download a Tom Tom app, it is a real turn by turn nav, pretty cool.
What does one have to do to program a "backroads" trip into a gps? Can you put in a road by road journey of your own choice? Or is it like Mapquest that gives you a choice of main highways or not main highways, but not roads of choice? The only reason I would want one is to do away with the turn by turn directions I now tape to my windshield.