I only heard a little about him from active JW. He was cast as an evil apostate and was told to avoid his book. I woke up in my early teens, actually on the day I was baptized. I'm thankful I only wasted my childhood in the cult. Well not really wasted as it wasn't a totally bad experience. My parents weren't uber JWs.
I learned about Ray Franz many years after I left and found his book to be more of an assurance I made the right decision. It confirmed what I deduced about the organization.