Well, I wrote myself a list of pros for both schools I've gotten into, so I can just paste in the Sinai ones (ps I had written these for myself, so these are the things that stood out for me...and they're probably not very well written):
1) Location: ON central park, next to some of the most amazing museums in the country, and yet bordering spanish Harlem. Can't get better diversity than that. And they have cheap tickets to events (operas, theater stuff), which is super exciting. Also, NYC is NYC. Amazing public transportation (won't need a car), food and entertainment everywhere. Other schools are nearby so you're not just stuck with the Sinai crowd all the time.
2) The Hospital: absolutely beautiful. Very prestigious and well-known. Their heart program sounds interesting (very interdisciplinary). The only issue I foresee is the fact that the entire med school is in the top floors of the hospital, which means a lot of elevator time. I bet that building gets pretty old. On the other hand, doing clinicals right there is definitely cushy.
3) The program: some highlights: the honor system (exams are put online on a friday, taken off on a sunday- you take them at home whenever you want), totally pass/fail with no internal rank, apparent close mentor relationship between students and faculty, research opportunities (you obtain a diploma with research honors), lots of random classes you can take, big humanities focus, the awesome transplant pager (as a first year, you can have the pager for the transplant team, and if they page you can go with them to get the organ). Other than that, it's pretty standard.
4) The dorm: so great! Big apartments, totally furnished, crazy cheap for Manhattan. Each room has a full bed (thank God). Great gym on the first floor, brand new stuff, pilates and yoga classes, etc. Doesn't really feel dorm-y at all.
Ok that's it. Hope it helps! Let me know if you have any more questions.