Right now, as a former UA 1K, and very happy (until last week) current AA EXP, I will stay with AA for the foreseeable future. Since AA has no minimum spend requirements a la DL and UA, I think I'd have no issue, especially with the qualification criteria, maintaining EXP status. I will miss the 4 extra SWU's, but knew that 8 was too good to last. As I purchase a mixture of premium and economy class tickets, AA will remain my carrier of choice, bearing future changes.
I'm curious and hopeful to see where UA goes with Oscar at the helm, but they have A LOT to improve upon before I look their direction again.