http://www.newyorker.com/reporting/2011/02/14/110214fa_fact_wright?currentPage=1
This is a very long article (26 pages!). I'm only part way through but it never fails to impress me, how similar some of these religions are to Jehovah's Witnesses. For instance, how publicly Scientology downplays their "disconnection" practice in the same way Jehovah's Witnesses do with disfellowshipping. Also noteworthy was the attitude towards those who had left the religion:
"It was also easy to dismiss people who quit the church. As [Haggis] put it, “There’s always disgruntled folks who say all sorts of things.”"
Edit -- here's another quote that echos the JW experience -
“The process of induction is so long and slow that you really do convince yourself of the truth of some of these things that don’t make sense,” Haggis told me. Although he refused to specify the contents of O.T. materials, on the ground that it offended Scientologists, he said, “If they’d sprung this stuff on me when I first walked in the door, I just would have laughed and left right away.