from my friends that have used them, not horribly loud as far as gear drives go. I think the POM makes a pretty big difference there in terms of pitch, and the housing tolerances are from what i can see, pretty tight meaning grease should stay on the gears more. I would try a set myself, but lately i’ve been on an all urethane streak and the 4gs doesn’t come in a size small enough to really work for my personal uses. (man, would i kill for a thane size 4GS with some good reduction lol)