well considering its done under anaesthetic.... pain isnt much of an issue.
Though i couldnt wear panties for a month, because the belend was healing. Also I couldnt walk for a day or two.....cause of the anaesthetic (hey I was only seven)
Yes it would be less sensitive, but in theory that should help a cut guy last longer, as it takes more time to reach climax. Im some cases, isnt this a good thing?!