I agree with Eastbay1k, I'd take the Amex Platinum lounge over the AC anytime. Last time I was there, they had 0 empty seats and the food selection was really poor (taste wise). Of course, if you can access LAN's lounge, that would be my number 1 choice (after the Centurion Centurion Room). And also, I can't understand why they closed the Centurion Lounge for a complete month less than a year after opening it. I was expecting some kind of upgrade, specially addition of hot food/snacks.
I'll be flying AA in July, I'll give all of them a try and update here. Its the later flight, so none of them should be very busy.