Punki,

I agree with auh2o. The Airbus 319 is actually one of the nicest coach experiences in the air, but since you can't upgrade, don't get double miles, don't get credit toward 10K/upgrades, 10K/confirmable upgrades, or million-mile status, I never fly Air Canada any more. Take UA all the way through ORD.

DEFINITELY visit the Maple leaf lounge in YYZ, whether you end up on AC or UA. It will spoil you forever.

And re upgrade certs...either the YYZ agents forget them completely or insist on 5 for the 2060-mile trip.