Just my .02 worth.

I was a long time UA 1K, so I may be a little more harsh on UA, but I feel I have a good handle on the airline. Being based in SFO, I would still lean towards UA, even with their abysmal CS and premium product, except for the fact you listed DFW, MIA, and NYC as you destinations. AA would give you much better opportunities on these routes. CLT is a crap shoot with either airline. DC area UA would probably be better.

As far as FF levels, this is really no question. AA EXP is the best taken care of flyer I have found in any program in the world.

Going TATL, to me, Oneworld crushes everyone else because of BA. I know LH is well thought of, and I think the put a good product out there, especially in F, but BA's J product is far superior. Their F lags behind SQ,CX and EK, but they aren't EU carriers.

Cheers
G