If you want a free and quick tour of Univ of Pittsburgh/free architectural tour, I would totally come here. Imagine having classes in different parts of the world everyday...that is pretty cool!
There's about 25-30 different classrooms. Tours available downstairs by the gift shop, but if you want to take your chance, just follow the building in any clockwise motion and wind upwards!
The highest story you can go is up to the 10th floor, but the fun rooms technically stop by floor 3. Everything above it is just TA offices/Faculty offices, and departments of different concentrations.
Ventilation is a bit muffy here, and so is seating. However, you're here to just check and go! Read the signs by the entrances to make sure you get your geeky facts of the day.
Overall, fun place! I would definitely spend about 30 minutes-1 hour here if you like to travel the world...but with a very low budget. ;)