I've only ever travelled once on AA in Y (LAX-JFK) and couldn't complain. The crew were efficient and friendly, and whilst I didn't purchase any alcoholic beverages the soft drink and water was flowing readily without needing to ask.
The rest of my AA travel has been in domestic F and on those flights I've had some of the best crews I've ever experienced on any airline including QF.
On a more recent flight from LAX-AUS we were diverted to DFW due to weather in Austin. The crew handled this splendidly and even continued beverage service while we were on the ground waiting for news on what was happening (we ended up refuelling and then flying to AUS).
Having said that, I concur with docjames - if you are travelling in Y and don't have any oneworld status, AA are truly a two tier airline.
The PriorityAAccess which is given if flying in F or if you're Oneworld Ruby or above is truly a life saver though when it comes to boarding and getting that precious overhead space (in Y) and even getting through security in a timely fashion.
Last year I was travelling with a colleague who was NB at the time. We were on separate bookings and he was in Y so he didn't get PriorityAAccess so we were split up at security. I'd have enough time in the AC to have a few drinks and relax, whereas he'd be basically running for the flight.
Besides, who can resist the delicious hot nuts and warm cookie that you get on some of the longer AA flights. That's much better than the packet of cashews/almonds that QF give you
I know this post is mainly about service, but if we look at the fleet - sure AA have some good and bad planes in their fleet just like anyone else. As an example, the ex-BA 767s that QF are using are shockers and don't even get me started on the 734s with convertible J that I always seem to find myself on