All but one of my banjos have 5th string pegs that attach to the neck in a plane that is horizontal and parallel to the fingerboard. Unfortunately the one banjo that has a perpendicular and vertical attachment is affixed to my minstel banjo that is both the easiest to play and has the best sound.
This banjo has a slotted peghead and mechanical tuners. It dates from sometime in the mid 1800's, and I would never do anything to alter its configuration.
The reason I say it is unfortunate that 5th string peg abuts downward instead of outward from the neck is that I have a heck of a time getting my hand from "first position" to the top of the neck without snagging my thumb in the process.. There are certain tunes like "Luke West's Walkaround" where this maneuver is mandatory and cannot be avoided.
Then it ocurred to me that many of you play copies of Boucher banjos which also have vertical 5th string peg placements. Do any of you have this problem? If so, how do you get around the fith string peg? I have tried placing my thumb on the back of the neck instead of wrapped around it, but this feels really awkward.