Easy to get around and well laid-out airport with little hassle. You don't have to walk too far to any terminal and there is a good amount of variety with respect to shops and restaurants in case one needs to kill an hour or so.
Free WiFi and all that jazz helps. I don't fly into Pittsburgh often, in fact I likely wouldn't travel through Pittsburgh on my way to another city. However, for those who do have the pleasure to travel through here, this is one of the better airports of a city its size.