Just in the past month I've had three cancelled flights (took refunds on all of them and booked a walkup fare on southwest or delta) and two delayed so long I blew an international connection. First time I got a refund and rebooked myself on lufthansa. Second time I took BA out and Finnair back. One of those incidents was weather, the rest were allegedly mechanical.
AA is an operational mess. Only my hatred of ATL is keeping me flying them right now, and at some point the need to reliably reach my destination will overcome that.