I've avoided AA for many years due to their business practices (reflecting Robert Crandall's personality - I'm not sure if things have changed since he stepped down).

Example 1 - I've exchanged tickets for friends and business colleagues on AA and UA. On UA I've done it many times without any problem. On AA, I tried it once. Even though the friend had asked the res agent to document in the record that I would be exchanging the ticket for him, AA airport ticket counter personnel acted as if I was trying to defraud them until I walked them through the scenario and got Res to explicitly OK the exchange by phone to them.

Example 2 - in the days prior to the routine ID check at the gate, it was Crandall's policy to confiscate tickets and tell the passenger he was committing fraud if someone tried to fly on a ticket that was not in their name. Not exactly a way to leave a warm and fuzzy feeling.

Example 3 - AA has been one of the most aggressive at going after those who use "back to back" tickets.

Example 4 - when UA and AA instituted their new programs with capacity controls and mileage expiration, UA was very honest in their ads (your original miles are good for six more years). AA trumpeted "Your original miles are good forever." What they didn't say was that UA continued honoring the original terms and conditions on their original miles (no capacity controls, very few blackout dates). AA immediately instituted strict capacity controls and blackout dates on their original awards.