Brandon Cronenberg came out and said there wasn't much of a difference in the NC-17 Cut. I'm guessing the orgy scene was more lewd. I also heard there was a close up of a penis ejaculating.

Vaginas, dicks and buttholes.

Shoot, I actually just read on imdb trivia that Infinity Pool was nc-17 but re-edited and won an "R" on appeal.

I said it in a previous discussion a couple days ago, but the cuts were definitely microscopic. Martin Scorsese literally removed 5/12 of a seconds from Goodfellas for an R. That much.

Infinity Pool's NC-17 was for "some graphic violence and sexual content". The R? "Graphic violence, disturbing material, strong sexual content, graphic nudity, drug use, and some language."

Further supporting this: The rating in Norway is an 18, the equivalent of an NC-17. And it's been rated as such for having "several strong depictions of drug abuse, sex, violence, and murder", with some of the murder depictions being "so close and grotesque" it rewards it an 18.