I've been flying U.S Airways for years, mostly on business. While I have encountered a few bad apples (every workplace has them), most employees at U.S. Airways really try to make your trip as stress-free as possible.
I give the employees a lot of slack, especially since they have to deal with handfuls of travelers who are sleep-deprived, stressed and half-incompetent. Some other passengers are just obnoxious "elite" members who pout when they don't get the upgrade that they are "entitled." I've seen these arguments dozens of times, which causes boarding to be delayed, then guess what the passenger starts complaining about?
My flights are usually on-time and the flight attendants are friendly (for the most part). I usually choose US if I get the choice. US Airways Clubs are clean and usually has a nice selection of beverages.