In general, I have found AA's cabin crew to be pretty good. You will encounter those that are indifferent to their jobs, or perhaps are having a bad day. However, I feel that is the exception and not the norm. Working with the public can be difficult and we all have our days when things don't go as planned.
That being said, I did see a F/A have an utter meltdown earlier this month on a trip. They got into a hysterical argument with a passenger that lasted the entire flight. They were also screaming up the jetway at the passenger as we were de-boarding. I have no idea what the argument was about and there are always two sides to every story. However, I do think as a service professional you need to take the high road and remove yourself (or the passenger if appropriate) from the situation. To be honest, I was embarrassed for this person as everyone within ear shot of me were making comments under their breath. I am a big believer in recognizing excellent service by sending an email to AA via their website when I receive service above and beyond. I also believe that when service is not good that providing that feedback constructively using the same form of communication is appropriate. After all, how is AA going to address it. I was actually called by someone from AA a few days later so they could get more information and apologize.
If you feel that service was far below normal, than report it appropriately. Be constructive and provide specifics. Also, since I manage a service team I have always found that it is always best to never make things personal. State what you saw. Most Managers really do like that feedback.