If I had my 'druthers (as they say), all my guitars would have 23 frets, plus a fretboard end-plate that functionally serves as a 24th fret, just like Jeffrey Earle Terwilliger's guitars did. (He retired, and the various brands calling themselves JET Guitars are not the same guy.)
Basically, I like the "bell" tone of Strat-style neck pickups. Part of that is positioning the pickup where Strats have it...which happens to put the pole-pieces where a 24th fret would be on a 24-fret guitar (give or take a millimeter or two).
But I also like having 24 frets, at least on the 1st and 2nd strings. (I never play higher than the 21st fret on the 3rd and 4th strings, and I top out at about the 18th fret on the 5th and 6th strings.)
So there's an obvious physical contradiction between those two "likes."
The Jeffrey Earle Terwilliger solution was to have 23 frets, and then put a little brass plate on the heel end of the neck where some necks have their truss-rod adjustment nut. (His truss rods adjusted elsewhere.) The plate would stick up just past the wood of the fingerboard and form a ridge which served as a 24th fret. This allowed his guitars to have 24 "frets" without requiring extra fingerboard wood on both sides of the 24th fret.
That, in turn, allowed him to move his neck pickups much closer to the traditional Strat location than he otherwise could have done.
It always seemed like a great solution, to me, and I wish he'd have licensed it out to other builders.