This is my experience for Air Canada at Montreal Airport.
I had an morning flight, I arrived 2 hours early. We went to the ticket machine to have boarding passes and luggage tags printed. The Boarding Passes came but no luggage tag.
We were directed to stand in the long line for check in. Eventhough we already had our boarding passes. During the wait I noticed that everyone who was late to the airport and had earlier flights were pulled out of the line and given instant service.
When I asked if there was a way for those who only needed a luggage tag could somehow just get it without waiting 45mins. I was told by "Michael" that
1. We tell everyone to come early to the airport,
2. Sometimes the "Machine won't Print the luggage tag because it wants you to check in with the counter staff"
He didn't apologize and his attitude was negative bordering on arrogant.
The flight was also late as was our connecting flight.
I have flown the national carrier for many countries. Air Canada is about as positive an image for Canada as United Airlines is for the USA.
When I returned to I saw in the News that an Air Canada flight almost killed themselves and four other planes on a Taxiway.
http://www.sfgate.com/bayarea/article/Disaster-averted-at-SFO-after-jet-lines-up-to-11281503.php
Ask any pilot this is really bad flying.
If I ever visit Canada again, I won't fly Air Canada.