I'll forward this post by putting it out there that I'm on the waiting list for LLU, but I was in a similar situation earlier when deciding between schools.
I definitely good to think long and hard about your choice of dental school, and to really focus on what you want personally, and in the end go with your gut.
I've heard that NYU has decent specialty chances, but I know that both NYU and LLU have numerous specialty programs of their own, giving you a bit of a foot inside the door. In talking with many dentists in the so-cal area, LLU is known for prouducing extremely competent General Dentists. Not too sure about curriculum differences though.
Another thing to take into account is if you want to move or not. Personally I'm not a fan of the big city for a few reasons, and that somewhat contributed to my turning down Columbia, but I've talked to many people who have said that living in the city was one of the best experiences they've had, and they wouldn't give those years up for anything. If you have relationships locally though, it would be understandable that moving that distance wouldn't be great. I know that's definetly a big factor for me.
Well, I hope that helped, and that I seemed balanced 🙂
Good luck, I'm sure that whatever decision you come to you'll be happy.