I, like many of the other posters, had the doubts first. Before that I would have not considered reading CofC. Therefore, the book confirmed my doubts. After I read that it was ISOCF and that was it. While I still occasionally attend meetings, not because I want to, but sometimes I go to keep family happy, in my heart and mind, I am done with it.
As was mentioned before, once you read both of Franz' books, I don't think you can ever go back to believing the BS.
My next project is Gentiles Reconsidered. I've heard that it was very enlightening as well.