Reading COC for me didn't make me leave. I had already left the year before. BUT it did help me feel better about my decision.
There are some disturbing things in there. If you are thinking of leaving anyway, well, it may help to push you. But, if you are just curious, it probably won't. Things that happen in that book were quite a while ago. Witnesses that truly believe in the WTS can reason that they governing body is not perfect, and one man's bad experience, and lack of faith, should make you leave. blah blah blah...and make you feel very guilty.
Hey, I say read it either way...you have a right to know the real story behind Franz leaving.