I can recommend going there on Fridays (I've been there twice on Friday nights, so far) and have been offered complimentary items even for take out. The sushi chef is Japanese and is very friendly. The ingredients are top notch and really fresh, so much so that I can actually notice the difference in freshness compared to other sushi places. The quality of the Nigiri Sushis and Makis I have eaten show the care and expertise in each piece. "Fresh Daily" it reads on the menu...Yes, I have to agree with that.
Update:
By popular demand (yup, one person hehe) I have added a Google Map image to show exactly where Banzai Sushi is...I guess there's a lot of sushi lovers in Montreal. Since Banzai doesn't seem to have their own website (as of this post) people are finding it through here.

Update (April 12):
New menu. See my comment below.