I love the hop on hop off tour format (I've done it in many cities) but this one was not worth the time or money. You are forced to buy a pass for two days so it's pretty expensive ($45 at least). To begin with, the bus was about 20 minutes late. The journey wasn't bad but it missed huge areas of the city (ex. Le Plateau, the botanical gardens & Olympic park...) - I can't imagine why anyone would be interested in seeing it more than once. The audio was simply terrible - we could barely hear anything upstairs (and based on the complaints I heard, downstairs was no better). It wasn't such a great loss though because the commentary was terrible... our tour guide didn't seem to know much and spent most of her time vaunting the merits of different companies and establishments around Montreal. Perhaps she gets a commission? Honestly, the subway system in Montreal is cheap (only $18 for a three day pass) and great, I suggest you buy a pass and discover the city on foot!