I fly into this airport a few times a year because I have family that live in Pittsburgh. I would give this airport a 3.5 because it's easy to navigate and for the most part it's pretty clean (some of the bathrooms by the terminals need to be remodeled.)
The main reason I don't mind this airport is because the security moves pretty fast every time I've been the it's pretty painless and goes by fast! There are several dinning options and the prices are pretty typical of a airport so no big surprise there. There is also plenty of shopping that you can do if that's what you desire.
The monorail to baggage claim is pretty easy to figure out and I've never had any problems there either. I also think parking is pretty affordable and seems to be plenty of it. The one thing I will say negative about this place is that it's been hard to find a decent cup of coffee and that sucks because most of my flights out of here are early in the morning.....