I just got into ATH from YUL, and my suitcase did not show up, but people on our flight who gate-checked carryon got theirs, and I was in J. We flew out of YYC with a 5.5-hour layover in YUL, my wife's suitcase made it, and mine didn't. It appears AC doesn't care we were business class all the way, and they still cannot even perform the basic task of just getting the suitcase even though it has a bright red "Priority" tag on it.