Are you on an int'l - int'l connection? Otherwise, unless you're departing perhaps on the last of the AA flights, the AA counter won't be open to get airside that many hours prior to departure.

The AA lounge is the least pleasant of the bunch - primarily because of the space itself, and how crowded it gets. The F&B is so-so. Location to gate depends on just where your plane is - it could be a one minute walk from departing the elevator, to a ten minute walk should you end up in the very low numbered gates.