It's only a single 3.5 hour UA domestic F flight (LAX-ORD on an A321neo, with full breakfast service) that we have to tolerate. The United customer service people could not get the LAX-YUL flight to book. It was use UA metal, or continue to play the purgatory lottery. I have no problem with the very comfortable UA Polaris seating for an overnight flight (food on UA is mediocre, but sleep is a higher priority). My return from Athens remains on AC J (ATH-YUL, then on an A330 to LAX).

I don't love booking codeshares due to this kind of messiness when schedules change (I've had small to moderate codeshare issues with AA, LH, UA, AC in the past since the 1990's). But the difference in price last October for two people combined vs booking J directly on AC or using all UA metal, was US $1,150. The only business class option that was priced the same as the bought code share was via BA, and I am not fond of their A380 plus try to avoid LHR like the plague.