All of these guys are borrowing very heavily from Michael Hedges, a truly brilliant, classically trained guitarist who is acknowledged as pioneering most of the slapping and tapping techniques. He unfortunately died in 1997 in an auto crash, but was often featured in guitar magazines of the 80s and early 90s.
I don't think many other guitarists have managed to match Hedges' combination of skill and compositional ability
Here are several videos of his work
https://youtube.com/watch?v=OPB-ShG_UWY
https://youtube.com/watch?v=0G75k...elated&search=
https://youtube.com/watch?v=29CMR...elated&search=
The guy that I think is probably closest to Hedges' genius is Don Ross:
https://youtube.com/watch?v=YkidVP0AcQ8