I'm not really too ashamed to admit what I've done in front of others. But I'm really only comfortable talking in one particular meeting of about 10-12 people, while uncomfortable talking in the larger groups --particularly if I see the same people at different locations.
When I say I'm comfortable revealing things, that means things I did while drunk, not the critical self-analysis and feelings that caused me to drink. Just as a guy in general, it never occurred to me to try and understand these things, let alone tell someone else.
After this last binge, I did go into this with my oldest sister w/o any real reservations. That said, I'd be uncomfortable with her being in a meeting with me when I told others. I don't know if that makes sense, but that is how I feel about going to regular meetings with a sponsor (as I understand their role thus far).