I did groups in a program that I was in for csa. They were all women. It took me a few sessions before I could talk. I felt just "lurking" was rude, and I finally disclosed a bit about myself.

I found the following:

1) It was quite helpful to see that others suffered the same symptoms as myself
2) It was really helpful to give feedback on things that I had overcome, reminded me that I was moving forwards.
3) It was difficult after divulging something personal to know all of those people now saw me in a different light. That was freaky and scary. In T you worry about what one person thinks, in group T there are several.
4) I would get triggered by personalities (similar to pc, but IRL it's harder to handle)