First off, let me say I am perhaps biased to do-it-yourself stir-fry restaurants since I am a huge fan of stir-fries in general. However, I love Open Sesame, I think it has a great atmosphere & delicious food.
Comparisons to Mongolie Grill have often been made; I will say that the do-it-yourself stir-fry is where the similarities end. Open Sesame has a full menu, the stir-fry is just one of the options. The ambience is about 100 times better since MG looks a little cafeteria-ish and is nothing fancy at all. MG can get pretty pricey, whereas OS has a flat rate of around $10 + meat choice $, no matter how much of it you pack in your bowl. It just seems more sanitary to me as well, since they only lay the vegetables out, not the raw meat alongside - the cooks add that as they cook it.
Other than stir-fry, I had delicious pot-stickers and shared a funnel cake that was sinfully delicious. The rest of the menu looks fantastic & I can't wait to try other features! I will definitely be back for more - it's one of my current Calgary favourites!