I just got home from Mike's house. Mike, thank you for the invite and I appreciate that you value my opinion.
Before I begin, let me just preface my opinion with my background. I am an audio research owner and have been for a long time. As a "tube guy" , what I heard was essentially similar to a typical solid state vs tubes comparison. The stellavox was like you'd expect from good solid state. Fast, detailed, neutral, dynamic and quiet. The dartzeel is a solid state amplifier that tube lovers can really appreciate. It's an ideal marriage of what solid state does best and what tubes do best. It has more body, tonal density, and big soundstage, but it's not giving up much ground (if any) on the details and dynamics.
We listened to female vocals, jazz, classical, opera, and rock. We used tape, digital, and vinyl.
On nearly every one of those selections, I felt like the dartzeels were just "right" for my tastes. The tonality, the rich midrange, the smooth but not glossed over top end. The bass control. I can certainly understand what makes these darts special.
There was one song with a fast guitar (maybe Mike remembers what it was, I was not familiar with it) that I will give the edge to the stellavox because it seems to excel with fast complex passages.
The stellavox is at a bit of a disadvantage today, because it's only got 100 hours on it, and was not on active isolation. Mike is putting it on the herzan today, and will be putting more time on it. Perhaps I will get back to hear if things have changed.
This is all subjective of course, either one of these are fantastic in their own way.
Thanks again, Mike. I appreciate the invitation and as always I enjoy your company and your system.