For now, I am flying out of DCA/IAD and STL. AA would work best for me because I could use the TWA 1st class line in STL. However, I would also try for elite status with DL and would fly them more if I need to make a connection (they offer some cheap fares through ATL). Does either program offer real upgrades? I know that I can "earn" them, but would rather use the airlines that makes using upgrades easier.