Shuttle America was pretty hideous in May, but maybe it's better now. I flew them 4 days after they took over IAD-PIT-IAD. Ancient Saab 340 both directions. Going to PIT, they couldn't figure out why they had 2 extra pax onboard. Kept counting and counting. Finally decided to go anyway! So much for security and bag match and all that! Turns out the extras were me and my travelling companion. We had used online check-in, but there was no scanner at IAD, so the agent merely wrote down our seat numbers. But of course he never entered us as having actually boarded the flight, so they let 2 employees on who were standing by. Coming back PIT-IAD, took a 3 hour delay with no explanation, no apology, no nothing. Luckily UA was proactive about it in IAD and had already protected us (in 3 cabin First!!) to SFO.
Hope it's better now ... anything's better than ACA.
PS
Still haven't got mileage credit for the IAD-PIT leg since our e-tickets show we never flew that segment. Ugh!