After one success with the Sanyo Pro-200, I began to feel confident that a phone based GPS would work. However, the following day, we used it again and I didn’t quite follow its directions, so it had to recalculate the route. Unfortunately it was far too slow at recalculating the route to be useful. It had to upload the GPS information to the server, recalculate the route and then send it back to the phone. By the time the phone got the information, I was in a different place and it had to recalculate again. Stopping the car and letting it figure out where we were got things going again.
I’m used to the GPS unit in my wife’s Honda CR-V and it’s extremely fast at recalculating its route. I’ve also used Garmin and TomTom units and been pleased. Before my next trip that I have to rent a car, I’m definitely buying a Garmin nüvi (the new ones look pretty cool) to save me a lot of frustration.