Hi Sharon,
I flew US Airways a week or so ago (from London Gatwick to Fort Myers, via Charlotte). I would have no hesitation in flying them again. The transatlantic flight is in new Airbus A330-300 planes (same on Man-PHL route). These are great. In economy the seating is 2-4-2 (rather than 3-3-3) so that families can sit together in the centre and couples do not have strangers at the side. Each seat has state of the art personal video screens with Video-on-Demand systems, so you can choose what to watch and when (I saw War of the Worlds, Mr & Mrs Smith, Wedding Crashers & Madagascar, for example).
Service was ok but not as good as BA or Virgin, but ticket was £250+ cheaper. In the US they are regarded as a budget airline, similar to Ryanair, so the US fleet tends to be older - and the flight from PHL to MCO is only 2 hrs 20 or so, so it is bearable. Unlike Ryanair seats are allocated.
Soft drinks are free on all flights but you have to pay for alcohol $5 or £3 a drink. Oh and you have to pay for your headset too if you don't take your own, but the cost £5 or so buys the headset so you can take it with you afterwards. The internal flights are shorthaul so there is no entertainment or food but there is a drink service. Buy something to eat at the airport instead. On the transatlantic you will get a simple choice of meal - pasta or chicken.
I would certainly use them again.