3.5 Stars
I came here in the summer of 2013 (three times) and honestly, I don't find it that amazing! The most memorable poutine was probably the one with a lot of peppers but in general, I feel that it's a bit over-hyped. The reason why I'm not giving them 4 stars is because of the long-lines and waits that aren't really justifiable other than fact that they're famous for their poutine.
The portions are really big and if you're not here for a meal (I don't really consider poutine + a pop a meal anywyas) then you can easily split it between 2 or 3 people as a filling snack. The location isn't exactly easy to get to if you don't have a car (we were here on vacation techncially) so the walk from the center of Montreal is perhaps 20-30 minutes depending on where you're located.
Definitely give La Banquise a try if you're in the neighborhood but if you're not a fan of waiting in lines, then you may want to consider one of the many other poutine shops in town! :)