Just from my very distanced standpoint, it sure seems like the transition from F to M is easier than the other way around....if you're not concerned about the genitals. All of these people could easily pass as guys both physically and vocally, whereas MtFs are often still stuck with their square jaws, large noses, Adam's apples, and low voices even after taking estrogen for quite a while.
And yeah, a lot of FtMs decide to stay genitally female because an artificial penis just isn't worth it, and a surprising (to me) number of gay guys don't seem to mind that at all.
The scars are more obvious than you'd think they would be....but they're also relatively recent for these guys so maybe they still have time to fade. And it helps a little bit that they're symmetrical and could maybe have some interesting tattoos around them.