I'm a Drexel student so I know the program pretty well. The hospital is not fancy and the EMR is not the best. But the attendings are amazing, like to teach, and are very approachable and there is a lot of dedicated teaching time. The work hours on the general medicine floor is really nice: 7 is sign-in, 5 is signout. The residents are happy and everyone is really cool. In terms of fellowships, the IM residents from Drexel's program matches very well. If you're interested in Cardiology, their Cards program is very good and they typically take half their fellows from inhouse (4 of 8 spots total).
I've never rotated at Jeff so take my comments with a grain of salt. What I am saying is second or third hand information. Jefferson has a beautiful campus but much less teaching and the patients are primarily private patients so the residents have less autonomy in management. If you're interested in GI, their GI program is excellent and I heard they only take their own.
I don't know much about Penn Hospital so I can't comment on how it compares to Einstein. I recently interviewed at Einstein and the program is solid. They do fairly well in fellowship match (was told it was 90%). What I didn't like about the program was that the intern rounds with the resident and not with the attending. If you hate rounding then this format might work for you.
The Philly programs are all very good. If you want GI or Cards make sure you go to a program with a GI or Cards fellowship. The other fellowships are less competitive and if you do well in residency, most likely you can match somewhere.
Hope that helps. Good luck!