Yes, I agree with all of the above. I remember a very impressive demo of his loudspeakers at Technology Park, Salisbury South Australia in (I think) the late 80's. A mate of mine had the Sovereigns with a huge sub built into the floor of his listening room. The first time I saw the throat of that thing I thought it was a sunken spa bath in the corner of the room. It sure tested the structural integrity of his house.
I also have a videotape of an old episode of "Beyond 2000", where they challenged a music professor to differentiate between live and recorded sound through the Sovereigns and Crown Princes. It was a bit lame as the "Prof" didn't impress as being able to differentiate his a** from........
I did have a pair of Crown Princes for a while but I was unable to get them to sound good, so I sold them. I don't think my amplification/sources etc at the time were good enough for the speakers, but I didn't know that .
I think that, after John left Australia, a couple of the Duntech senior staff founded Sonique. Duntech still exists in NSW, but they seem to keep a lower profile than they did in the "glory days" in SA with JD at the helm.
John is one of the industry greats - I hope he's not as sick as the news suggests.
