I'm a second year at PCOM and I think it's a great school. Everything is brand new (library, gym/activity center, OMM lab, etc.) and the faculty and administration are really focused on educating good DO's. PCOM also has many affiliations throughout Pennsylvania and some in New Jersey and Delaware which means lots of options for rotations and good post-graduate programs. At the same time, they continually evaluate each rotation site so that every student recieves a comparable and solid clinical education.
The basic science curriculum is system-based except for anatomy, biochemistry, and molecular biology. Some people like it, some don't, but it's the same with every curriculum.
Also, Philadelphia is a great city in which to study medicine with 4 other medical schools in the city whom I've heard are pretty receptive to osteopathic students in terms of rotations, etc. Some of the profs at PCOM also teach at other schools in the city (DOs and MDs alike).
PCOM does give preference to Penn. residents.
In short, I'm very happy to be at PCOM and I feel as though I'm at the best osteopathic school in the country.