I put 50/50 and 'most people don't know'. More and more often, I get long, hard looks lately, and no pronouns used at all. I find that people who don't know me have been pegging me as male more and more often lately (still with no T). It really pays to watch your tone, inflection, manner of dress, and mannerisms.
Also, I was deflected out of a women's bathroom at a movie theatre today. Very glad at the time that none of my family was with me.