Are future improvements in Amp/PreAmps slowing to a crawl?

@csmgolf 
GO READ THE THREAD AGAIN, you LIAR. I do grill the guy hard, but only because after a very lengthy and civilized back and forth he still answered no specific questions, even when I literally laid out a simple template of what I and many others were genuinely wondering. I'll gladly listen to anything anybody wants to send me, but I'm not doing it at my own risk and expense. 
If you want to believe whatever jargon he slings, fine with me, but I'm over here evaluating things in a different sort of way. I'm sitting here writing this listening to a rig which, with the exception of the speakers, I've either built or rebuilt with my two hands. I'm in the habit of knowing what I'm playing with in an intimate sort of way. I'm not a man of unlimited resources. If I want to listen well I must learn, meticulously evaluate things, understand circuits, hear distortion, and discern causes and effects. I just want answers that actually mean something. I'm rather befuddled so few others do as well. 

Roger believed in his product enough to let you hear it for yourself. To test the device in question. IOW, he put up. You, on the other hand, irrespective of the circumstances, HAVE NOT put up. It is that simple. Everything else is chest thumping.  
I have in no way said that I believe what he has said. If you could please point out where I said that, I would be grateful. On the other hand, I have not discounted it either. I am curious though, what exactly would you "risk" by listening to this piece of equipment? Your pride? Your beliefs? Financial obligation aside of course. I would love to audition one of these. Of course, IF (note I said if) I found it to do what Roger says and reported it as I heard it, I would be labeled a kool aid drinker, a dupe, and subject to confirmation bias because it cannot possibly be so. It would be better if one of the people that claims this to be snake oil actually test it in their own system and report what they heard. If you heard Roger's device do what he describes, would you be man enough to come back to these pages and report that?

I can’t afford for something that expensive to be damaged in use or transit and be in the hook for it. That’s the risk I’m talking about. The specs he states on his site suggest it should sound decent. Does it perfectly replicate the recorded material? No. I don’t need to hear it to know that. But that’s the claim he makes, isn’t it? Haven’t I and others politely asked for a rational explanation? Have we gotten something other than snake oil jargon?
The point of this thread was to discuss Nelson’s statement that amps are a solved problem, that there is no technically perfect amp, and that they are, for all intents and purposes, art. But a few folks here, and chief among them Roger, piped up to claim designers are giving up, aren’t trying hard enough, and are failing to think outside the box. Those strike me as bold statements from people who’s experience and success pales in comparison to the likes of Pass. Those kinds of bold statements deserve bold explanations for which there have been none at all. It’s like when Leonard Suskind stuck his neck out to call Stephan Hawking wrong about black holes. People demanded a bold explanation. And he provided one. That’s what elevated him from a plumber to a physicist.

Kosst

The point of this thread was to discuss Nelson’s statement that amps are a solved problem, that there is no technically perfect amp, and that they are, for all intents and purposes, art.

I understand that it is his viewpoint or opinion but it is not factual.
His mission or target or goal (according to the article) is to make an amp with a particular "sound" or signature.

Pass:

There are few things I enjoy so much as to contemplate the specific (and complex) characteristics of the many transistors (or tubes) and how they might fit into an amplifier to deliver a sound which has a particular signature.

Rather than go through all the devices as if they were shades of paint on a mixing palette - I prefer to make an amp with "no sound".  By default in order to have a "sound" the amplifier modifies the pure input signal to include a form of distortion or corruption based on the devices used. It is not necessarily bad thing but I don't want to hear the parts - the only thing I want to hear is the music.

As far as bold statements - I am trying to be polite. I have a policy of not criticizing or speaking ill of other designers. Mr. Pass by his own words is not seeking the perfect amp. I am.

I could give you a few bold statements of fact but it generally won't sit well with some individuals that post or read this thread. It would be good news for some and bad news for others.

I think the engineering science to design and produce a straight wire with gain reached sonic perfection in the 1980's. The next advance was in improved manufacturing technology that made such amplifiers considerably cheaper (unless you wanted the mystique of audiophile stuff that ironically was often far worse). Right now, and I suspect even more so in the future, the technological drive will come from the need to be more energy efficient. In Europe, mandatory standards of energy efficiency are tightened for more and more products. For example, our recent vacuum cleaner that comforms to new EU standards uses only half of what the previous premium model did, and is far quieter and lighter to carry (and it sucks dirt rather better). The same is happening everywhere, and the only reason that e.g. class A amplifiers have not yet been outlawed is that there are probably too few of them around. But new TVs have to meet pretty stringent legislation. I suspect this is a large part of what is driving class D developement.