Was supposed to fly YUL-YYZ-ZRH this afternoon but my YUL-YYZ flight was delayed from 2:00 to 2:35 but didn't actually leave until 3:09.
As a result, the AC concierges re-routed me on the LX flight (delayed by an hour

). Poof lose my likely upgrade (or otherwise bulkhead), lose the extra Q miles from flying back to YYZ and longer flight to ZRH and get 25% rather than 100% bonus miles for LX vs. AC.
That got me thinking that when AC posts a delay, I'm estimating in my personal experience that they fail to meet that revised timeline most of the time - probably over 80% for me.
What is your experience?