Air Canada had screwed me over many times, you can call it Stockholm syndrome but I still won't touch Flair & co with a 10-foot pole. Even with Porter is a big hit or miss. it will only be my very last resort (Shelled out $800 to Porter once for BOS-YOW because it is the only airline that can get me home the same night).

AC's network and interline agreements are often worth the premium they charge. One time I got stranded in Boston due to weather (incoming flight cancelled), they were able to book me on the next flight to LGA on Delta then YUL on United then YYZ on Air Canada. Porter customers next door were told good luck and see your tomorrow.