The biggest difference among the three schools is the class size. Buffalo has 85, the other two have like 35 - 40. Gossip/rumors travels pretty fast within our class of 90, in a class of 40 it must be instantaneous. You will be bound to find some people you like and relate well to in a class of 85.
But class size aside, I guess a big difference I can see is boards. UCONN likes to tout its incredible board scores on their website. They really beat that medical stuff into your heads the first two years, and in speaking with a student there, you don't really get too much time off to study for Part I. He said many of his classmates would walk into the boards and take them based on what they learned in class b/c they just didn't have that much time to review. We had 5 weeks off to study for the boards, and many students who were serious about trying to score 90+ treated that study time like a job to achieve their goal. I don't know if it is worth the medical hell for the first two years if you want to be a general dentist. Or even a specialist, you will never use that stuff again. (Except if you do a 6 yr OMS-MD program where you have to take the medical boards, then I guess taking those insane classes is a plus). I suppose it depends what your ultimate goal is. If you want to be a general dentist, definitely come to Buffalo. They love that at our school. If you want to specialize in craziness (endo/ortho/OMS), I'd be more inclined to say choose UCONN, but then again, you can specialize coming out of Buffalo. It's just that the percent of students specializing out of UCONN is higher than Buffalo, and they have that whole P/F system in place, so I don't think they have class rank. My guess is that with so many students specializing, their faculty are more inclined to be supportive of the students who choose to do so.
I liked the facility at UCONN, but I think our clinical experience is probably more comprehensive than theirs. This is from 2001, but the upperclassmen explained something about how one junior & one senior "team treats" the patients together. Like the junior does the amalgams and the seniors do the crown preps. Again, not entirely sure on that one. You'd have to look into that more. Here we get our own patients assigned only to us junior and more assigned senior year, and you are responsible for doing all of their treatment (except anything too crazy that has to be referred to post-grad).
I've never seen Stonybrook but I've met a bunch of their students through ASDA and they are a fun bunch. They complain about clinic, just like we do. The students did tell me that Stonybrook's pedo dept teaches them the hand-over-mouth-technique (a self-explanatory behavior mangement technique) while hand-over-mouth is severly frowned upon at Buffalo. Wierd that the two schools would have such different approaches to pedo, but it could just be due to one faculty member influencing the department in one way. Stonybrook doesn't have too many post-grad programs, so I don't know who ends up taking their crazy cases (maybe it's the gazillion dentists in LI).
Visit all three, and talk to upperclassmen and recent grads of each school to be sure about the info on each. They're all good, I think it's probably a matter of personal preference when trying to decide among these three schools.