We used them this past January for a trip to the US and I would be hard pressed to use them again.
During the flight the cabin crew managed to miss us (and the 2 rows before and after us) on every single food / bar run, when we ended up having to get up yet again to ask for our meals the implied apathy from the stewardess was that we should be grateful that she was even lowering herself to talk to us.
Delayed arrival into Atlanta meant that we missed our onward flight and there was no information on what to do, where to go, finally got directed to the correct desk for rebooking to a later flight, but without a modicum of apology / customer service.
My biggest concern was that on an internal flight they had children sitting at the emergency exits, although my understanding is that there should be an able bodied adult... when I mentioned it to the cabin crew I was made to feel like I was stealing candy from the kids!
The actual planes seem antiquated (as do most of the cabin crew, but thats a different discussion thread) if you have flown with a carrier with personal entertainment units recently, forget it, its 1 screen in the middle of the cabin and hopefully no-one will stand up!