5 Saisons was one of the best sushi experiences that I ever had. I live in New York and actually spent two weeks in Tokyo earlier this year, so I have "high standards." My girlfriend who is Korean was feeling homesick and so we went looking for Korean food one night while in Montreal. We couldn't find any place that was open but saw 5 Saisons, which has a somewhat striking exterior - like a house set back from the street.
First, the rolls with soy paper wrap (or something like that) and the chef's special sauce - were amazing.
Then, the shrimp and vegetable tempura was delicious and more than plentiful.
We are back in New York, and still talking about this place. I actually want to return to Montreal just to eat here, at least every other day.
One plus is also that it's BYO.