From what I understand, if you're a paranormal or erotica author, you're in good stead at RT, but if you write stuff more like what I write, more realistic family drama romance, there aren't as many fans of it attending.
But for erotica and paranormal writers, you'll find lots of fans. (I'd guess that historical would also find a number of fans.)
I've heard that it can be sort of...rough...especially for the male models. What irks me is that were those models female, and the molesters (and make no mistake some of these guys get molested...like that poor woman's husband) male, there would be hell to pay.
Susan G., who has never been to one, so is only offering second-hand information.