We parked on one of the neighbouring side streets with free parking and originally had plans to eat somewhere else. But it was so cold out we didn't want to keep walking and ended up here. What a lucky accident!
As other reviewers have mentioned, the menu is not very extensive. About 5 different taco entrees, 2 enchilada entrees, and a half dozen appetizers. Compared to Matraca (the only other mexican taco place we've tried in montreal) this place was much tastier, more authentic, and slightly cheaper. (Plus free homemade chips and salsa!) The main drawback compared to la Matraca is that it's not designed as a taco tapas resto -- meaning tacos are priced as entrees (3-4 per order) and not as single items for you to try a variety. But based on the authenticity and tastiness of what we ordered (pastor tacos and chicken mole), it's likely that your best bet is to just order whatever sounds yummiest to you and you can't go wrong.
The grocery section is very limited -- about a dozen items for purchase (with about half of them being authentic mexican soda varieties), and service can be a bit slow with only a few staff members on site. But service is very friendly and attentive, and atmosphere is casual and nice.