Disclaimer: my sister and I are from LA and therefore have access to really good Korean food. I don't know how many Korean restaurants there are in Montreal, but will be reviewing from my perspective/experiences.
Kantapia is conveniently located near the Hilton Garden Inn on Sherbrooke- my sister and I went to Kantapia around 6:30PM and were immediately seated at one of the counters. We were served pretty quickly, but service was a little harder to get a hold of in the latter part of our dining experience. Banchan (side dishes) were limited to two.
My sister chose a bulgogi with noodles in soup (I forget the specific name of it) and my one sip of it was actually quite good. I don't think we've seen this dish in other Korean restaurants (or maybe have just missed it) but it was quite good. I stuck with the Dolsot Bibimbap. Food was good but nothing spectacular. I could definitely see how this would be hot comfort food during colder weather/winter.
Although not apparent, customers are supposed to go up to the counter to pay for our food. At this point, the restaurant was packed and employees were running around looking a little frazzled. A large group of guys ended up getting all of their cards run by one of their own (I guess he's related in some way or form to the restaurant) but he shrugged at us after paying for his own portion and headed out. The waitress who replaced him afterwards looked a little unfamiliar with the machine.
Overall, 3/5.