It would depend where you are starting from; from central Philly, maybe about 40 mi. Slightly closer to Lancaster, but not by much. Either way, 3 1/2 hrs. each way was cutting it close for me when I had to be at work by 5:00 am next morning!
I had a chance to see Stryper in Pittsburg once, but that was an 8 + hr. trip for me. We considered renting a helicopter! Hey, when you want to see your fav. band, you'll consider trying anything to get there!