Lateralis, I like Jon, love some of the work hes done for atz but he's still a little new compared to the more seasoned players.
Here's a nut that Jon did for a friend of mine. It's not the best nut job ive ever seen. Tuning was very unstable and the raduis of the strings at rest were way off vs the fretboard. Notice how all the strings go in too deep into the nut. Also notice how the nut is angled instead of flat to support smoother string pul (this is how les pauls have to be because of the awkward headstock and angled direction of string pull after the nut, specially the G string)
This is what it should have looked like:
Please don't get me wrong, im not bashing Jon, like I said hes done some good things, he's just not up there yet (but its IMHO which isnt the law).
Edit Add: I also wanna point out that showing some faults in his work is not a bad thing, I really hope I'm not embarrassing him but am only showing these things so that people become aware of what to look for in a guitar. If no one knew that his nut fabrication and installation was wrong, he'd never get it right.