We've gone through Atlanta with Delta a few times without issue. Once, we even were able to make our connecting flight in ATL on the way to MBJ with only a 40 minute layover. Our arrival gate was about as far away from our departure gate as possible too. The "Automatic People Mover" (tram/train system) at ATL is very quick and efficient. Though I did have a sigh of relief as I looked out the plane and spotted our bags being loaded.