We signed up for the 3 hour Heart of Montreal tour. Priced at $50...reasonable. We did cover most of the main attractions, Mont Royal, Notre Dame, Neighborhoods, Olympic Village and more. Very thorough. The problem was the guide. There really should be separate English and French tours. Our guide, Germain, had a heavy French accent and it was hard to tell which language he was speaking as he went back and forth from one sentence to the next. He also made what I considered to be a very inappropriate comment as he was describing some senior housing. He said it was for "retired/retarded , whatever" people. Not exactly the type of comment one is used to listening to on a tour. I would have liked a bit more detail about the city but again, too much back and forth in two languages. The bus was way too hot too. People were in winter coats.....no need for all that heat. I also did not appreciate the high pressure to tip the guide.
All in all worth it but your guide makes all the difference in the world.