A lot of fun, great food, but the noise level was a bit much and made it feel like a place where one scarfs food down and then exits fast. It's cavernous two, more than 100 seats easily. The papaya salad was great: explosion of flavour in the mouth; we opted for salted crab with ours -- whole pieces, shell and all, which might not be to everyone's taste. The chchirones and prawn crackers that come with the dish are perfect. The best dish was the pork pad gra prow, nicely flavored ground pork with rice and a runny fried egg. The Khao Soi disappointed: egg noodles in a very rich, maybe overly rich, lightly curried coconut soup with shrimp (one can also order this with chicken or beef) . Staff were very good, but the ambiance, or utter lack thereof, kills it. Maybe good for takeout though. Nice to see they have locally brewed Izumi sake on tap.
Chris Nuttal-Smith more or less nailed it in his Globe review: http://www.theglobeandmail.com/life/food-and-wine/restaurant-reviews/with-respect-and-disappointment-pai-northern-thai-kitchen-serves-some-of-the-best-thai-in-toronto/article19970065/