I've been here a couple of times with friends (~4-5ppl) and there is always a wait during dinner time. However the food and service is definitely worth it!
We keep our orders pretty similar each time we visit because we've come to crave exactly these dishes:
-papaya salad (served on a platter with vermicelli, veggies, fried pork rinds, shrimp crackers and of course the salad itself)
-beef salad (beef is always VERY tender)
-tom yum soup (big bowl, amazing flavour, comes with a mini flame to keep it hot)
-beef pad thai (generous portion, not gooey, just the right spice level at Medium)
What I have to commend Pai on is their exceptional service despite the level of patrons, servers are always around/asking how everything is. Bravo and I'll definitely be back soon!