Experiences with lost luggage with AA: 1) came in on the very next flight and was delivered to our hotel in the middle of the night to our hotel room--I tripped over it going to the bathroom in the morning because all 4 of us were sleeping so soundly the hotel personnel actually put in our room without us waking up; 2) arrived after 2 days in Hawaii with no clothes--but at least it was warm there (we weren't naked, just didn't have any changes of clothes and I had to sleep in my underwear which was interesting given that my 2 teenage sons were sharing the room); 3)lost for 4 days but finally arrived--it was ok because this time we were at home.
All in all, I think AA does a pretty good job of tracking down luggage. But being able to track baggage on aa.com would be great.