The 3 biggest negatives about NYU seem to be 1) cost 2) large class size 3) lack of training in root canals.
1) There's no way around it, NYU costs a lot of money as does living in NYC. Nova being a private school, I would have to assume that it would cost a lot as well, although not as much.
2) Depending on what type of person you are and what type of environment you do better in, the large class size can be a positive or negative. Personally, I don't mind the large class size. I like to be able to hide out if I choose to, but I also take the initiative to meet my professors.
3) Having such a large patient pool, I doubt that you would lack any clinical experience. In fact, I would imagine that you would see tons of cases you would see in your future practice as well as some cases you may never see again.
I don't know much about Nova, so I will only say some of the positives I've heard. Most of this is what an oral surgeon was telling me.
1) The dental school is well-integrated into the other professional schools (med, nursing, etc). This provides you with training not only in treating dental conditions, but also in seeing how conditions of the oral cavity affect the overall health of the patient and vice versa.
2) Brand new school with very nice facilities.
For whatever reason, NYU seems to be "picked on" the most on this website. Maybe some of the people have valid reasons, but due to the large number of posts that are all centered on disproven rumors, I would have to believe that many of the people are simply adding to the rumor mill.
But to be fair, maybe I'm slightly biased b/c NYU is the only school I've been accepted to thus far. However, I can honestly say that I really liked what I saw on-line, in the brochure, and at my interview as well as what I heard from NYU students.