My sister who circ'd her only son and I were talking about this last night (I don't know how it came up) -- I told her that we were still planning on an intact son if we ever have a boy, and the conversation went from there.
Her ds is circ'd because "his dad is," but mostly because although she (an RN) knew at the time that the research didn't show benefits of circ, she had an RN coworker who'd been at Desert Storm who told her about "all the adult circumcisions that they had to do, and how awful they were," so they circ'd their son.
I told her I hadn't run across that in my research, but had run across some references to how upset some of the men who'd been circ'd were about the sexual results for them afterwards; and that I figure, if I have a son I hope that he can keep himself clean and doesn't go to war. I don't want to plan his life assuming that he will go to war (even assuming the 'war' argument is correct, which I don't think it is).
Anyway it was a good conversation - she said, "We didn't know as much then as we do now," and I told her, "I know, it's a journey isn't it?" I think if they had another son, they wouldn't circ (based on our conversation). Which is GOOD, because although that's not going to happen for them, that means that hopefully she can advocate with me on the anti-circ front with other siblings who are expecting (we are from a large family).