AC also lets you cancel a ticket within 24 hours, no questions asked. With Expedia their policy is not published and up to their discretion. I once booked a ticket at 2:45am EST and called 11am the next morning to change it. They said that because I had booked it "yesterday" I could not (they go by PST). I spent an hour on the phone with them (2 different agents) and they refused to transfer me to a manager.

They've also transferred their call center for expedia.ca to Egypt. If you can speak French, you can get someone in Canada still.

I use Expedia if I have connections that start and end in the U.S. or Europe. Otherwise AC.