I rarely (perhaps never have) flown YYZ-YVR in the morning. I like to have the day available in Toronto, in case something comes up. And travelling in the late afternoon/early evening, and almost always get my upgrade.

I suspect that a lot of business types like to fly in the morning, because with time zone differences, they "appear" to land shortly after takeoff. If one had a meeting in Vancouver at noon, it would be easy, and probably perferable to leave Toronto at 8am to arrive in Vancouver at 10am, as opposed to leaving the night before and staying in a hotel.

So based on both our experiences, and a "buncha hunches" it sounds like the later in the day flights are better for upgrades.

Regards,

Ken Hamer