As a trans service provider, I'd like to offer my input from experience.
In addition to working as an escort, I also work as a street prostitute. As an escort, my ads are quite clear about the fact that I'm transgender. As a street prostitute, that is not the case. Men who see my ad are specifically looking for a transsexual woman. Men who pick me up on the street have no idea that I'm a transsexual, at first.
If they just want a blowjob, then as far as I'm concerned there's no need to tell them what's between my legs. If they try to grope me, I move their hand away and tell them "that's high value territory, you haven't paid for that". If they want sex, then I tell them that I have a penis.
I have regulars that just want head, and they have no idea I have a penis. I have one regular who I finally told after a few months of just giving him head, and he was completely ok with me having a penis. And there's been guys who've picked me up and who've either slid their hands into my crotch faster than I expected, or who realize up close that I'm a transsexual, and have said, in various ways, that that's not their bag, baby.
I was completely unwilling to disclose that I had a penis at first to street clients. I'd make up excuses like "shark week", recent surgery, etc. in order to dissuade them. I finally got tired of constantly lying and told a regular, and after his positive reaction, I decided to disclose to all my street clients.
The positive reactions have been quite surprising! I don't know whether it's them being comfortable with me, more extensive and positive media exposure, changing attitudes - but quite a few guys who picked me up not knowing I had a penis have been completely into it after being told. I've had a couple of guys ask if I was a man based on my voice, my height (5'10"), and I simply respond, "No, I'm not a man. I'm a woman. I do happen to have a penis though, is that going to be a problem?"
Maybe it's living in a smaller city, maybe it's client age (the older people get, the less they seem to give a shit about things that would bother younger people), maybe it's good old-fashioned Canadian politeness, but I've never felt endangered upon telling a client that I have a penis. The worst I've had to deal with is young people driving by and yelling shitty things.
Working the streets as a transsexual woman is the ultimate test, I think. It's been enlightening and very uplifting. Maybe I've been extremely lucky, but I'd like to think my positive attitude and general attractiveness make the difference.