Love it. Must try while in Montreal.
If you live in Montreal, annual membership is so worth it.
Very convenient, and if something goes wrong you can phone them. Very helpful.
Website tracks your riding info etc. Very convenient.
When you return a bike, make sure you see a green light. You might get a fine of $200 etc.
Bixi isn't built for a long ride. It's made for stability and frequent stops and safety etc. (Not for racing, not for endurance. It's made for tourism, convenience, and commuting)
Montreal has a nice bike network. Best online map for bikes here: http://www.pedalmontreal.ca/