Enjoy Atlanta! Its a great city with a really cool OSM Community. You might want to try to get in touch with the local community to try out your new GPS :) There is an OSM Georgia Facebook page and wiki page that has everyone's contact info.

The map of Decatur, GA (3 metro stops from downtown) is amazing! There are a ton of great places to eat and see.

Best,
Thea

There is a great mapper in Chattanooga named Randy. I'll pass this on to him.