I just returned from my trip to State College (had a meeting at Penn State). I went through Bellefonte on my way in on Monday. Got to the APS a little later that I hoped, but still had about one and a half hours there before they closed at 4:30. I briefly toured the build, loved looking at the stamp displays on the walls, then spent the rest of my time going through the circuit books. Got some nice Turkish stamps to add to my collection!
Then, before driving back home today, I decided I'd go back for a couple of hours, which I did first thing in the morning (this morning). I spend my time in the gift shop, and I purchased 30 stamps and a whole set of used Scott catalogs...total bill was $7.50
On Monday, I did walk around the library a bit, but found it to be a bit overwhelming unless you know exacting what you are looking for.
Overall, I had a great time, got some nice stamps for my collection, and picked up some much needed catalogs cheaply without needing to incur any shipping charges! And it was a beautiful town and a beautiful drive up from Maryland.