On our current trip from Los Angeles to Spain, every leg was canceled, delayed or took 3 hours for checkin due to lack of staff in the Barcelona Airport. We paid for seats that we did not get when we waited for 8 hours for our flight and was moved to Luftansia.
I can say the only consistent was fail to perform.
We are now waiting in North Carolina for our final leg where they delayed indefinitely due to lack of crew. Our group will never fly American Airlibes again.