Went to IUP last year so the Knob was my "home" mountain. Must say that I can't get enough of it. It has plenty of vertical for those of you who keep track of that. The terrain is easily the best in PA. I have skied almost every mountain in PA and I can easily say that the double diamonds here, are actually double diamonds. They don't give them that rating for no reason. They have the only bowl(that i know of) in PA. And when there is enough snow, the glades are amazing. The mountain is never crowded, and the people are very friendly.
Now on to the negatives. #1 The snow making is not that great. The best time to hit this place is later in the year when they have received a good amount of snow. #2 They have no high speed lift. The chairs are terribly slow, so if you are skiing top to bottom, prepare to get chilly on the lift. #3 Not that it bothers me cause I don't use it but the lodge is very small and outdated. There is nothing. Just skiing. #4 Park rats need not apply. They can barely say they have a park cause it is terrible.
One other thing to keep in mind, it gets very windy and cold. So dress warm.