Buffalo has more research opportunities (NYMC is not a research-focused institution) which would be helpful if you later chose to go into academic medicine or a competitive speciality and you said you liked the vibe at Buffalo more (NYMC struck me as dreary; I've never been to Buffalo). I'm not sure what the grading system is at Buff, but I know NYMC is basically graded (something like honors, high pass, pass, fail). There's no discernible difference in prestige or ranking. I know you said you weren't considering cost, but it sounds like you're in-state which makes Buffalo a lot cheaper than NYMC. I feel like Buffalo would be the move unless there's someone/something really important to you in Westchester (like a spouse or close family).
Match lists vary every year and it's hard to compare Buffalo and NYMC's match lists. NYMC is a private school, so it has students from all over the place and so their match list reflects that in geography as well as competitiveness. Buffalo is public, so it has a lot of NY residents and probs a good chunk of Western NY residents who want to stay, so I imagine their match list reflects that.
