If you're in the McGill area then you should definitely check this place out especially if it's lunchtime as the prices here are cheaper then. It can be crowded at lunch so it helps to have a reservation however you can also get it to go so that can be another option. In my experience at dinner it tends to be less busy and they have a second section of the restaurant that they open up as well so for that time you generally don't need to reserve.
I usually get the beef japchae which is a sweet potato noodle dish. It's pretty good but I wish it would be more on the spicy side when I ask for it like that. They also serve a kind of fish soup with it and a side dish which consists of a sampling of three different sides. They tend to change up the sides from time to time but kimchi is usually one of the options. I'm not a fan of the fish soup but the sides generally are pretty good.
For the price you can't go wrong with Atti. In general main dishes are $10 around lunch time so it's only a tad more expensive than the food court factoring in tip and tax however it's far better quality-wise.