Well, I think I can answer this pretty well since I rotated at both places.
Rochester: It is an academic program for sure. Excellent NIH funding (top 1,2, or 3 each year) basic science opportunities up the wazoo with a musculoskeletal research wing in the hospital. Comprehensive program with no holes whatsoever. The attendings are all pretty good to work with and doing a trauma rotation is a blast, since the trauma guy there is a great teacher and a good guy to be around. Major downfall is probably lack of early operative experience. 2's and 3's don't get much operating in and usually are first assist when they are in the OR. Also, as a 2, you do a few months as the "pit" resident where you hang out in the ED and basically get slammed by consults and trauma. Good thing is, you only have to do it for a few months, then it's over, home call as a 4-5, usually as a 3.
Buffalo: Much different "feel" to the program with operative experience early and often. Most of the 2's I talked to log about 6-9 cases a week and they are usually doing most of the cases. Academics/research is not up to Rochester's level, but it has made some strides forward since hiring the new director of research. It is also a comprehensive program with exposure to every subspecialty. Trauma is seen mainly at the Erie County Med Center and there is no lack of it. Residents are a hard-working bunch who almost never complain even if they are getting slammed with consults, traumas, etc. Overall, the operative experience is first-rate.
As far as living...well, the winters are long and cold with crazy snowstorms at both places. Rochester is a very "live-able" city and is great if you are married or have family nearby. Not so great for meeting young people and the nightlife is luke-warm at best. Buffalo is also alright, but underachieving. Bigger city, more to do, nightlife is actually pretty rockin and Niagara Falls is less than an hour away $$.
Basically, that is all I want to write at this point, but if you have any further questions, give me an email...
good luck!