Worth every penny!
This is the second set I have purchased. The first was for my Line 6 JTV-59 (FYI not a direct retro fit but I'm cool with that). The gold ones I put on my 1997 Guild JF-30 to replace the stock Grovers that were given to tuning instability. OK so they are NOT a direct retro fit either. The screw on the back of the headstock lines up nice but be sure to check your tuning peg hole dimensions. The tuners need a 10 mm or 13/32 sized hole. The Guild JF-30 tuning holes aren't 10 mm all the way through. There is about an 1/8" lip at the faceplate I had to drill out (that is a permanent mod so be as sure as I was that you are ok with that). PSA- Please only work on your stuff if you have the tools, ability and confidence to proceed, otherwise have a skilled tech do it.
It turned out fantastic! Now I have a pleasant and notable difference in sustain! The locking and trimming mechanism is perfect and I'll put them on every guitar I own from here on out. I value the tuners more than what I payed for them.