I love jimping, but only if it's about as fine as a file.
I want my jimping to grip my thumb without having to dig into it. With the super fine jimping that I like to add my thumb can almost slip right across it until I add just a bit of pressure, then it comfortably grips and holds without hurting my finger.
IMHO if the jimping isn't fine and file like then it's just decorative and shouldn't be there.