I think you'll like AS an awful lot, I know I do. For all the reasons mentioned above, AS is completely superior to WN (it is not a no-frills airline at all) and a cut above UA. Upgrades are NOT that hard to get if you're planning in advance by say, 30+ days or so. Some of the U class seats are released "up front", some are released as the flight date gets closer and the revenue seats are released. It can be challenging getting transcon upgrades, but not as tough as previously mentioned.