the wharton school reserves spaces for med students every year for the mba. i'm not sure if harvard does this though. also, if you're interested in health policy type stuff, i believe wharton can help focus your track towards that.
agreed...harvard will get better name recognition overseas, but why the hell would anyone wanna go overseas unless s/he is mother theresa or something?
either school will get you a top-notch residency.
penn's curriculum philosophy is geared towards boards performance, and you won't hear a lot of lectures that focus on what the lecturer's research interests are. last time i compared numbers, penn students do better on step one than harvard students (it might be different now, however). either way...as i said before, residency matching will be the same.
boston is way better than philly (my opinion).
living is cheaper in philly.
dual degree at penn is easy to do and highly encouraged by the administration.
library at harvard is much much better.
research at both is top notch.
harvard's hospitals are, in general (probably minus BID), better, but i'm not sure how much that matters to med students. teaching and the faculty's quatlity of teaching is what really matters. i know that in the past few years harvard has added some incentives to their med school professors to place more emphasis on teaching. whether this is because of poor teaching or attention towards students previously or just a measure to increase the quality of teaching, i don't know.
harvard, as a school, has more money and might be able to better help you out financially.
P/F at harvard is very nice. penn is h/p/f (to me, this sucks) after the first semester, and essentialy straight-up grades in the clinics (but grades in the clinics - h/hp/p/s/f - is the standard at almost every school). both schools, however, have very motivated and amitious students. so just by being in that company you'll work your tail off regardless of grade policy. at either school, though, i'm sure you could get by just passing comfortably.
the med school at penn is better integrated within the university, even though you'll have to make an effort to "mix" with other people from other schools. hms is in the longwood area, whereas the rest of the university is 15-20 mins away (depending on traffic) in cambridge.
that's all i can think of right now. you're very fortunate to be in such a situation. make sure you try to attend the second look weekends. though it's difficult to make a definite judgment on the student body in just one weekend, it's better than nothing. it'll be nice just to see the night life in boston/philly, see what the students supposedly do on the weekends, get a feel of an "average" day at each school, etc. hope this helps! PM me if you've got any other questions.