Burned through my first T+ flight pass in the last month (exclusively YYC-YYZ and return) without a single waitlisted upgrade clearing. I travel at close to peak times for business travellers, but I'm impressed with AC's load management - flights are always jam packed.

Had on one occasion the experience (noted by others) of having R space open up on a flight, that I am waitlisted for, within 24 hours of check in (expertflyer alert). Promptly cancelled check in, cancelled upgrade request, requested it again and, voila, confirmed.

I'm getting used to the poor man's upgrade - exit row, a roast beef sandwich, and two teeny tiny bottles of red wine.