>> I've heard mixed reviews on GPS devices; any opinons?

A gps will lead you down stray roads just as readily as Google maps cycling option. Both require judgement to stay out of trouble.

I use the cycling/walking options to rough out a route. Satellite, street views, personal knowledge, and common sense to assist with refining it. As I don't use gps at all, I transfer the Google route to paper maps. If I wanted to use a gps, I'd transfer the route over to www.ridewithgps.com and download the waypoints.