left my car home, rode with a buddy.
we used a Garmin C330 from Raliegh to Athens NY to Savona NY thru PA, VA, and back to Raliegh.
it was ignorant.
it had us on roads there were not even striped/painted
it had us get OFF the main road (501 south in VA) and take back roads across town, to get BACK on 501 south on the other end of town.
i would NOT get one based on that unit's performance.
everyone raves about Garmin though, so my buddy is going to try a update on his via the internet. it's 3 years old, and it was total crap.
you could SEE where you SHOULD go, and it would tell you to turn a different way.