I'm not even a med student so take what I say with a grain of salt. I have a lot of toes to psu Hershey (went to psu, shadowed physicians at Hershey, many friends work there and a few friends currently at med school there).
I had the program basically described to me as you losing the summer after ms1. Other than that the burden on your studies isn't that much greater. But obviously it locks you into a specialty and residency program so ultimately you gotta decide if that's what you want. Psu Hershey is a great place for residency in anything, though.
Congrats if you got offered this!