Check out the US Airways forum at FlyerTalk...a few good threads on that, and with information coming straight from the mouth of B. Ben Baldenza, who runs DM
As for mile transfers, you can do points.com and transfer them to AA
, and a few others. First transfer is free. Keep in mind that the conversion ratio is horrible.
As for miles, they're fine until December/January. After February, I might be doubting U's existance, but until then, I'd fly them (I just booked a trip on them last week to go to Boston next week, and if I have any other travel needs this year, U will get a serious look).