Perhaps I am just an outlier, but out of the 9 AP classes I've taken, only one was intellectually stifling. Intellectual curiosity was far higher in them than in any regular class I ever took. The demand to keep pace up to learn enough material for the test wasn't strangling us to death, but simply made sure that we weren't wasting too much time. We spent a lot of time in each class doing creative exploration of topics and many fun projects and whatnot. Most of the time we were learning a lot and loving what we were learning. It was only in the two or three weeks before the AP exams that we cracked down and began focusing strictly on problems we would encounter on the AP test. Compared to the non-AP classes, we learned far more, did far more, and were more free to learn how we wanted to and do projects that we wanted to.