I know it doesn't matter what any of us say, but I'll still say this: For the unions at AA to be backing US Airways is a big mistake. Management at US Airways is just as horrible, if not worse than that of AA. I know everyone at AA is pissed at AA management, but US Airways will not, I repeat, WILL NOT be better towards you. US managers are big on deception and inaction. Any promise that US makes is just that, an empty promise. And the longer they can drag out fulfilling their promises, the better it is for them.
The grass in this case is not greener on the other side. I guarantee you that.