I think the question is how touch sensitive we are.
1) the part where the frenulum touches the head - I think that's the male g-spot
2) the rest of the frenulum remnant.
3) the head, and especially the front corona
4) the meatus when touching lightly when hard
5) one side of the scar on the underside and the shaft skin below. I know, wierd, but true and only in recent years and with very light touch. The skin when erect is really tight there.
Overall, I feel I've got more erogenous zones than before being cird. it's counterintuitive.
And it's possible to have that nearly cumming feeling and not come. I had problems or premature ejaculation b4 cutting and now it's almost the opposite!
Just for that reason it was worth it.