I have three - two big fender-type ones on a precision & a jazz, plus a gotoh 'Y'-type on an Epi T-bird. I keep a tiny tin of vaseline with my pliers, cutters & allen keys to keep 'em greased up but they don't need much attention and they work perfectly once they're set up properly. I've only had to adjust the little thumbscrew when changing from one type of strings to another. If its set up correctly the tuning stays spot-on in both positions.