First of all, where are you from? If you're looking for a cosmopolitan atmosphere (and relatively expensive), go to Chicago. If you're looking to save money on medical school, Buffalo is cheap tuition-wise (if you're an in-state resident, or you can obtain residency after about a year) and as far as the cost of living expenses. Buffalo is a nice town, and close to Niagra Falls and Toronto, not that you'd have that much time to spend at those places. 😉
As far as the quality of schools, med school is med school. If there are better opportunities at Finch that you feel that Buffalo isn't able to offer, then go to Chicago. Otherwise, Buffalo has a lot of great research opportunities, their students have a positive reputation in being known as hard workers, and the faculty and staff are very supportive. I know several students at Buffalo, and overall, they're pretty happy. The only negative impression that I got when interviewing there was that Buffalo has a tone that is not super confident (i.e., they didn't really sell the school to us, in my opinion). If I didn't know people there and get their impressions, I wouldn't have known how great it was. I can't speak on Finch though.
Good luck in your decision.
H&T