I never understood why zero frets aren't used more often. It's the same as using a capo. Maybe it's to cover up sloppy fretwork & setup. I've seen a thousand sales pitches about how superior bone, micarta, ivory, fossilized dinosaur turds, yadda yadda are the perfect nut material when in fact there are only six notes where the nut actually matters, and only one that can't be played elsewhere. I would think it's arguably superior, since all notes would bear against the same substance and be more uniform. Plus, if it's good enough for Dr Brian May, I'm down with it.