@gdnrbob Thanks for that. Great article.
I now recall that I bought a used PS Audio Perfect Wave P3 about five years ago. It was in my system for about a week, then I sold it and went back to the Blue Circle. I don't remember why exactly, but there seemed to be less "life" to the music with the P3.
It's possible with a bit more tweaking it might have been better, like how they treated the conditioners in your linked article.