I originally posted this in a discussion on the Manhattan board concerning Pam Real Thai's quality, and thought it should be over here (with some minor editing). Siam Square is on Kappock Street, right off the northbound Henry Hudson parkway.
I live near Siam Square and have eaten there often (plus lots of take out). The service is very friendly and perfectly competent. The food is always good, and of good quality (ingredients-wise); the style has always seemed somewhat Frenchified to me, and the chef's specials often have a continental tone to them. The spicing is what I'd call medium, but then that's what I prefer, so I cannot tell you if they'll heat it to the level some posters seem to prefer without losing the flavor balance. Their porpia are lightly fried and delicate, their drunken noodles have lots of basil and pepper flavors, and their penang curry is rich and tasty, especially with duck. Other dishes I've liked there include deep fried wonton-like dumplings stuffed with sweet potato, tiger cries (flank steak), a tempura type watercress salad with onions, chili, and lime, and a dessert of purple sticky rice with mangos.
I haven't eaten at Sripraphai, so I can't compare the two, but I have eaten at Wondee Siam, and I'd say that the food at Siam Square is comparable, although not at the bargain prices; however, Siam Square is a far more pleasant place to eat then Wondee. I can't really say if Siam Square is worth the trip to the Bronx, but if you're in the neighborhood, it's certainly one of the best options.
On reflection, and reposting, it may be the best option.