Hamburgers in Montreal? Why not? My wife and I went on a Saturday night at 7pm and the line was beginning to form out the door. The restaurant is small with just over a dozen tables. The waiting area could probably fit about 10 people whilst blocking the door. The two of us waited for about 20 minutes before we were seated. If there are more than two of you expect to wait longer to be seated when it's busy.
The burgers were pretty damn good and the fries were even better. I don't know what's done differently to the potatoes in Montreal but I like it! Accompany your burger with some blanche beer and you're golden! If you're looking for a cheaper dining option and don't mind waiting a bit look no further.