I tried this a couple of weeks ago - and it turned out to be a complete disaster. Dep. Jul 18, Ret. Jul 21 - wanted to make the most of two and a half business days in the UK. So I booked YOW-YYZ-LHR, flight 866 on latter segment, so that I would arrive at 7:30 a.m.

Upon slightly delayed arrival at YYZ, was told to proceed "urgently" to the infield terminal, where I found the departure was delayed from 7:30 p.m. to 8:45 p.m. Returned by shuttle to T1 and MLL. Flight 866 was delayed several more times, and I made two more trips to the infield terminal before departing at 2:00 a.m., arriving LHR at 2:30 p.m. (7 hours late) and the day was shot. I'm sure this was an anomaly, but this strategy didn't work for me.

There is much more to this horror story, but I won't bore you with the details.

AC offered 7500 AP points, but they haven't shown up yet...

Greg