I owned one of his earlier guitars(an archtop), and it was a great instrument, capable of a greater depth of sound than I have heard in any other instrument, but very demanding of the player(too demanding for any of the the other Zeidler owners I ran in to to actually make it their main instrument)--

I had a number of discussion with him about the relative virtues of the classic archtops, and he tended not to think much of them-- as I understood it, he thought that electrics were much better instruments, and he wanted to get the dynamic range and cleanness of sound that they had in an acoustic instrument--

He once built his own version of a tele, semi-hollow body--that impressed me even more than his acoustic instruments--it had the bite that you would expect, but the sound was very complex, with a lot of dynamic room--Bob Benedetto said that John was the best luthier that he knew of--too bad to loose someone like that--