For me, I really needed CoC. It confirmed so much of what I was already thinking/feeling and really exposed the Watchtower in the gentle and kind way that I needed. Anger just turned me off and made me think "apostate" and shut down. Ray Franz had a fantastic way of expressing himself.
In addition, he destroyed the illusion of the Governing Body, which I really needed. As a r&f witness, you are constantly asked to look up to and revere the gb. You are told they have a special helping of Holy Spirit and deep closeness with Jehovah. That they are specially equipped to interpret and understand the scriptures. That they are the most humble and like Jesus. Even though I was already strongly suspecting otherwise, especially after Anthony Morris III came on the scene with all his hateful vitriol, I needed that confirmation and proof.