Based on responses here, it seems like today's AA favors more of the pmUS hubs, with the exception of DFW (which was pmAA's main home hub).
I wonder what's wrong with ORD, though? It's nice because it's a competitive hub with UA, it's centrally located, and it also commands more premium fares, IMHO, due to it being an attractive midwestern major city and metropolitan area. So, why do you think AA has been cutting ORD?
IMHO, I think CLT is probably the worst hub in the system. Tight, smelly, crowded, surly employees with fake Southern friendliness that goes out of the window fast... I'd choose even PHL over CLT, IMHO. Why would AA want to choose CLT as one of its top hubs? If CLT was in a sparkling new building with huge facilities and plenty of room (like JFK), then I'd understand, perhaps.