I've only flown them once, but I will be flying home from LAX on them next month. Our first experience was somewhat shady. We flew BOS to ATL, which was fine, except that we got to ATL late so we really, really, really had to book it to get to the gate where our connection was. When finally got to that area, there was a flight to LAX loading, and a flight to LAS loading. It was a chaotic scene. No one knew where they were supposed to line up, there were no reps around, and then the door to our gate closed! We were like ***?!!? and then someone opened the door and we went down the gate to our plane. No security alarms went off, and no one EVER checked our boarding passes. We were able to get seats in the exit row (woo hoo), and then even more people continued to get on the plane! Once we finally took off, we overheard a woman in front of us say something along the lines of "I can't wait until we get to Vegas!" and all around people were mumbling...."um, we're not going to Vegas...." The poor woman got on the wrong plane and tried to tell the flight attendant we needed to turn back because SHE was going to Las Vegas. It was really quite humorous for the rest of us- she wasn't really hostile, she just felt like a total idiot for getting on the wrong plane! Anyway, when we landed in LAX I was telling my DH there was NO WAY our luggage was making the flight, we had too short of a layover in ATL, WE barely made the flight. BUT lo and behold our luggage made the flight and our faith in AT was restored.
BTW, this flight was a freebie when AT and Wendy's had the cup promotion, so it was tough to complain about a free flight.
A friend was supposed to fly from BOS to MCO a couple of years ago, and his flight was rescheduled several times and he finally canceled his AT reservation and was able to get his money back. We fly home on AT, as I mentioned, next month, and our flight has also been changed already, but it as only by 15 minutes so it's not a big deal.
I remember the seats on the plane being spatious - it might have been the exit row though. We're SW people usually, but again, we had freebies from the AT credit card...