It used to constantly frustrate me, being seen as less capable pre-transition. I would have arguments with mechanics about what was wrong with my car, what was a necessary repair, and what could wait. I felt compelled to know everything about my motorcycle and car so that I could speak from knowledge. Now I don't bother, I just take it into the shop and get treated as though I know what's up even if I haven't a clue. Job interviews, there was always a vague suspicion (now I would say confirmed) that my gender was affecting how my abilities were perceived. I am physically stronger now, but even before having that extra strength, been seen as unable to do something that I was perfectly capable of was beyond aggravating.
At work, I could give someone sound, solid legal advice from my experience and training and still be doubted or questioned far more often than I am now.
As a white, able-bodied professional, male privilege is very noticeable and the lack of it was something I always suspected, but couldn't really nail down what made me suspect it. It does tinge every interaction. Also men speak with other men and reveal more than they do when they speak with women. It doesn't give me a lot of faith that male privilege is going away soon. There seem to be some basic, unshakeable ideas held by a lot of men that women really are less capable.
It may be, too, that I was hypersensitive to it because of the dual effect of it on me. Being seen as "less than" and also being seen as female, neither of which I felt like.
As to the effect of acquiring male privilege, I have to confess that my initial reaction is like that of a lot of abused children I've spoken to when they see their sibling being abused: "oh, thank god it's not me this time". Then it makes me uneasy. I don't do enough to combat it, because I still feel vulnerable to it. I get worried that someone is going to bring up my trans status to dismiss anything I have to say about women's abilities.
And to speak to Diana's point, which I think was addressing the other thread, I noticed and railed against male privilege from an early age. It affects children too. Being treated differently because you are a boy who is feminine is not the same thing as suffering from the effects of male privilege. It is an awful experience (having had friends who were born male who were treated very badly for not being masculine enough), and stems from similar roots as sexism, but it's different. Male privilege is when you are a little girl who can play baseball as well as her friends, but isn't allowed on the team because it's boys only. It's when you're not considered as smart as the boys in your class. It's when, even though you have the same physical strength and are as tough, you're considered weaker and more vulnerable. It's when all the adults in your life ask boys what they want to be when they grow up and assume you want to be a wife and a mother, or that you'll get a temporary job, always teacher or nurse, until you get married and have kids. Maybe it's a bit different today, it's not as blatant as it was when I was growing up, but it's still there.