Been here twice on short trips to Montreal. Definitely worth the experience. Because it's a unique concept, it's really more about the experience than the food (though no complaints about the food either; I was more than happy to go back).
I'm really not sure why there are two-star reviews from people grumbling about having to eat in the dark. Did you not know what the whole point of this place was before you went?
Overall, the food and drinks were satisfying enough for me to feel justified in paying for this. Just make sure you wash your hands before you start eating, because you will most likely need them to find your food!