We've never flown US Air before either, but we are booked through them for our December trip, so I'd be interested to know people's experiences as well.
I already have a "D'oh!" and "Whew!" story, though...
We are flying from Minneapolis through Chicago O'Hare to Orlando, and we were booked the same route in reverse coming home.
For some reason yesterday, I checked my reservation, and US Air had changed the last leg of our return trip from O'Hare to Minneapolis to an earlier flight! Our flight from Orlando to O'Hare is scheduled to land at 8:10 p.m., and instead of the 9:40 p.m. flight to Minneapolis (which now apparently doesn't exist), they had us on an 8:30 p.m. flight!
I'm not sure how they thought we were going to make a connection that tight, so I called Expedia (where I had booked the tickets), and had them check into it.
They agreed that the connection wouldn't work, and they called US Air to get a different flight.
Fortunately, they were able to get us on a flight from Orlando to Charlotte, and then Charlotte to Minneapolis-- with around an 1 hour 45 minute layover in Charlotte (which I'm much more comfortable with).
So, I'm glad they were able to make the change (at no extra charge, of course), and I'm fine with the new arrangements, but I don't know why they thought we would be able to make that Chicago connection, and didn't bother to tell me!
(I'm also really, really glad I checked into this now, rather than having a big surprise in December!)