I didn't go to a group. I am guessing though that the amt of gender expression is going to vary pretty widely. It was funny but I answer the phone with my first name. I came in the center, the guy kind of looked at me up and down (and I present very androgynously right now) and he says "You don't want to be known as *that* do you?" He got that part right.
I had just the opposite experience of, well he told me a lot about T. He kept going back and saying, well everyone doesn't take T, this is just my experience. I feel that it was a bit of a stretch to him this non-binary thing but that he was working on it.
I am still not sure I would go to a group, but I enjoyed the real life element to this. I definitely feel at home with trans* people. I did not feel that they didn't think I was trans* enough (though there is this meme going about).
--Jay Jay