Pai is great. Not just great but one of the best places to dine in Toronto in terms of deliciousness. Their authentic pad thai is a must try. The sweet-salty-savoury flavour they have developed surpasses all expectations within the city limits. Their Thai Iced Tea is so complex with flavour. Do not be discouraged with the amount of ice they put inside. Drink it slowly. The flavours change with the ice melting.
The ambience is always busy and for good reason, the food and service is delicious. Expect a bit of a wait if you're dropping in.
Speaking of the service, once they accidentally made my (now fiancee's) Pad Thai mild when she asked for no spice (she's a lightweight when it comes to Scovilles) and they took it back immediately. The owner came out to profusely apologise and also comp'd us 50% of the cost while rushing the order through so we can still eat together.
The quality of the food and service justifies the price (and it isn't that pricey).