Thank you everyone for your insight and personal experiences.
Living in the more conventional world of multi-driver solutions, my belief system for amplifiers was that you get what you pay for. This was unraveled somewhat with the amp Sam Kim built for me. For me, a step up in SQ for less money.
For someone who loves the Horning sound, I was taken at a show when the amp was switched to the $3,000 SS Audioprojekte CA10. I realize, if I spent more time comparing the Audioprojekte against the default Tron, I would probably pick the Tron. Still, the rule of diminishing returns seemed to almost disappear when compared to differences with other types of audio components. I consider the CA10 a super value, and it was the reason I started to investigate the subject of this thread.
I agree and understand that the amplifier must be dead quiet in order to achieve the sound that we seek. At the same time, I don't want to give up the "life" that great tube amps fill into that dark space. For example, I was put off by a $100K Krell system with the quietest and darkest of backgrounds. Add to that great pinpoint imaging, but with a flaw. The players floated in their own bubbles with no life (air) between them. This is my own opinion, but I became bored as the sound seemed cold and uninvolving.
Okay, probably by now you know what I like and prefer. Additionally, I have a smallish room (16 X 14') and require an intimate sound. Even so, by gravitating to the Hornings and Rethms it's also obvious that I require some bass. The woofers of the Rethm are powered, but the Horning woofers are not. Perhaps, this makes the Rethms easier to drive with a more cost-effective solution.
While Sam Kim's amp is brilliant, and he can build me any push-pull triode that I can think of, I'm not sure about the needed silent background for these highly revealing drivers.