As I have always said, Atlanta is a great place to live, but I wouldn't want to visit here. MARTA rail from airport is fast and efficient, one of the few good things about the system. If you want to leave the airport, that is the only way I would do it in your circumstance. Beware of security lines at the airport, they have been awful lately. Also the traffic is some of the worst in the US. Nothing you can see in Atlanta is so good as to risk missing your next flight for it. I think the security lines on the international side are quicker than on the domestic side. The length of your layover is too long to want to spend it hanging out at the airport, but not long enough to really do anything without risking being late for your next flight. Frank's suggestions look very good to me, It will be a good choice to let yourselves relax and walk in Piedmont Park or the Midtown neighborhood and should cause you little risk of being late to return. Lots of restaurants, cafes and bars, shady streets, fine old houses in good repair. Unlike Bs. As., however, Atlanta has hills, so walking may be harder than you expect or are now used to. Safe travels.
James
