In my personal experience from the mid 70`s to the late 80`s, in my congregation of perhaps 100, there was one person with genuine learning difficulties, one paedophile - convicted and prisoned,and one Elder who left, and took 6-7 followers and joined the Baptists.
That`s what I knew, and that was only because I was involved with someone who`s Father was an elder. The rest varied from "normal", ie: enjoyed life in their way, to those who lived and breathed eveything the WTS uttered, but still were near enough "normal".
"Were they just better hidden or controlled", almost certainly, the pedo was informed that he must not say in court that he was a JW, and the local newspaper didn`t mention it as far as I can remember.
From what I have learned over the past few months, the WTS has changed in many ways over the last 20 years, so like Scientology etc. I think that being a JW may now attract those who are to a normal "Joe Bloggs", apparent Spacemen. Though, as I personally have no interaction with JW`s at all, it`s pure speculation on my part.
Saying that though, they`re still mad, bad and dangerous, IMHO.
Regards
Paul UK