I had a YYZ-YVR flight a few weeks back; I specifically picked a flight that had me on a 1-2-2 767.

Then AC did the old bait and switch, subsitutuing it for a ratty, run-down 2-2-2 in J that features useless seats.

I understand that this happens due to operations, but it is frustrating as heck, and I would barely call these "perfect flights." There is such inconsistency in the J seating that it's a real crap shoot as to whether you are going to get a good flight or not