Pusadee's Garden is right down the street from me and definitely a staple. Not only does it have some of the best Thai food in Pittsburgh, but it's outside seating is absolutely beautiful on a nice summer day. In the evening hours, everything is lit up and the ambience cannot be matched anywhere else in Pittsburgh.
The service is great but can get a little bogged down on busy nights. The food is flavorful but conventional Thai fair. Their most interesting deviation is their street noodle dishes, which I don't see on too many Thai menus in Pittsburgh.
Their heat scale is hit or miss. I've had a 10 here and while I perspired profusely, I felt like I was still not experiencing the dish as it would have been served in its home country.
While Pusadee's Garden did replace the only Filipino restaurant in Pittsburgh (to me and my girlfriend's chagrin) it replaced it with a formidable Thai component in the slightly over-saturated Thai food market of Pittsburgh.