A note about the Marta stop: when you get off the train, only go up ONE level, not two - the middle level exits directly onto Peachtree, within sight of the Grenada, as Jax said. The top level, however, has an exit that faces a different direction, and you can't see the hotel or the venue around the station behind you. Because I'm a dork, I ended up on the top level, had no clue where the fuck I was, picked a direction to walk, and it was the WRONG direction.
This time I know better. *g*