Seeing as you are going to Schwartz Deli, if you guys are up to the task, give
Lester's Deli a shot for a back-to-back comparison to Schwartz. Lesters earns a top spot of one of my favourite places in Montreal for smoked meat sandwiches. Interesting characters and neighbourhood regulars hit this place up. Owner is a bit of a funny guy. Don't let the menu fool you; You can opt for just the sandwich only and share a combo between the two of you guys.
Also, for Schwartz, if you haven't been, there are two sides to it. One is the original restaurant and often has a line up. Next door to it on the left is the take out location without the wild lineups if you guys don't want to wait in line too long. Ask for medium fat.