I work for a Delta regional, but commute on AA quite a bit. The difference is night and day. On my last commute, the people behind me paid for Main Cabin Extra, and the FA wouldn't give them more than 1 free drink. The gate agents are all very militant.
When I was working a home based charter job, I would purposely buy Delta, even if it was more inconvenient, commuting out of DFW, because it was a better experience.
They really need some customer service training all around.