The trouble with AA (and probably UA) are the cost of earned upgrades. It would have cost me 7 upgrades each way to upgrade my recent trip, or 17,500 q-miles, on AA. 14 earned upgrades or an equivalent of 35,000 miles of flying r/t. Mind-boggling 28 or 70,000 q-miles if I upgraded someone else as well.
Despite all of US's new shortcomings in FC service, it is a lot easier to earn upgrades.