Decent airport with nice shopping if you have time and money.
PIT is unique from many airports because of the shopping mall located in the central area. I actually cannot afford any of the goods sold here since prices are so high, but shopping is fun even if one doesn't buy. And if you have a long layover it is enjoyable to browse and dream. Even so, they can take a lesson from Narita Airport on how to mix high end with affordable.
Restaurants are all mediocre as best as I can tell. I've dined in several and don't get that " I have to fly through PIT more often feeling!" They aren horrible though like the restaurants at Philadelphia, Shreveport or São Paulo airports.
If you love football, look for the memorial for hero Franco Harris and if you like dinosaurs there is a t-Rex greeting travelers as they exit the train.
I would give PIT four stars if they had better connections. I'm fine flying direct from Houston but it seems strange that I have to fly through Philadelphia when coming from Syracuse.