Great product, Makes a lot of difference in sound and play ability. To say nothing of staying in tune. I put one on a Ovation Legend made in 1972. The guitar always sounded good but was a little tough to play. This made a world of difference. It is now amazing. I have a friend who can't keep his hands off of it. He likes it better than his Rainsong.
The Zero Glide performs like the manufacturer claims it will. It took less than one hour to complete the installation and have the guitar playing. The nut I removed was cheap plastic and the thin wires had cut down into the nut to the point that there was severe fret buzz on the open strings. The Zero Glide cured that and has all of the strings at the same level. I used a disc sander to shape the nut to length and height in a few minutes. About five more minutes and the nut was polished. The installation looks good. I suggest a person view the manufacturer's installation video before doing the installation.
I bought the mandolin version and fitted it to my Gibson. There's a lot of extra material to remove, but the result was great. Easier tuning (the old nut had tight slots for the A strings), better intonation. Later I used one of the extra frets in the package to fix a tenor guitar. For that, I simply filed the necessary ledges in the existing nut and widened the string slots. It would be nice if Stew-Mac would also sell the offset tang frets separately, for retrofitting to an existing nut.
My third build and first time I used the zero fret, made filing the nut slots easier. The sound is markedly clearer than the other bone nuts I've used.
I wrote another review about Zero Glide and my Gold Tone OB 150 banjo. As many already know the Zero Glide Nut is standard equipment on the OB 150 banjo. Gold Tone has this nut on other instruments too. I like this nut system for a lot of reasons. I installed a Zero Glide nut on my Martin D custom and I even installed a Zero Glide on my Washburn M3SWK F body mandolin. Those stock plastic nuts on many of the entry level pro instruments just does not cut it. You are cheating yourself and your audience out of a lot of tone and sweetness that ears should be hearing. The Zero Glide nut does a world of wonders for my instruments. Do yourself a favor and get one on your axe. You may love it. I know I do. I am addicted to Zero Glide.