It really depends for me. I've been hit on by several gay men that I went to school with, who wanted to have a sexual experience with a transman. I'm not okay with that. I can understand how it would appeal to them, and I can understand that for some transguys, that kind of offer would be appealing. But I don't like being approached for anything simply due to the fact that I meet a niche sexual interest. Like someone said earlier, it just doesn't seem to take into account that I'm a person with feelings.
But if it's more of an emotional/mental thing, I can dig that. Both of my most recent girlfriends enjoy being with transmen for very specific reasons, and I don't feel put out or objectified or fetishized by that. I'm okay with people having preferences as long as you can articulate why you have those preferences, and the reason doesn't boil down to an acute interest in my anatomy.