I have a lot of experience listening to the current crop of high end gear, and know several people in the industry including some, who I call friends, who very sincerely trade in 'tweaks' that I find entirely suspect. They're sincere in their belief, really...at least my one good friend is. So I wouldn't call it fraud as much as I'd suggest there's naivety even at the dealer level. And while I know that expectation bias exists in all of us, I think that some people are just more ripe for it than others. But there are outright charlatans and I have seen them behind the scenes letting their mask down a bit.
But to answer this question, even though not directed at me. I have heard amazing hi fidelity systems. A lot of them. Some cost thousands and a few were over a million dollars. I've also heard bad hi fi systems in both of those price brackets. All that said, the best sound systems I have ever heard were all in professional recording studios. And while a lot of that gear was -very- expensive, especially the custom monitors, none of it looked like most of the 'hi fi jewelry' you speak of. It looked more like the Benchmark amp you denigrated. And the ADCs and DACs weren't pretty (but some of them were indeed expensive).
Personally I have a mixture of objectively chosen gear, and gear that I admittedly preferred for subjective reasons. The camps aren't as black and white as the online tribalism would suggest. You can prefer something for illogical reasons and it doesn't hurt anybody, while also acknowledging that adding objectivity into the decision process is NOT a bad thing at all. Especially in an industry as rife with obvious charlatans and easy marks as this one.
As for the Topping DACs and high end systems... my Topping D70 sits alongside my (original msrp) $11,000 EMM Labs SACD player and sounds every bit as good. Don't assume that all of us who run such things as the Topping haven't heard the stuff you consider to be 'high end'.
Now, for the amp in question... for many of us it isn't so much about this amp as it is a final straw for the way hi fi companies have been openly insulting of the intelligence of us, their customers. This is my first post here, though I've taken many of the measurements here into account, before, when buying things. For the life of me I cannot figure out why anybody thought Mr Carver was a magician who could do what no other tube amp designer could do with 19lbs or metal, especially when listening to both him and this Frank fella talk about it in the most obvious used-car-salesman schtick. There's a fanboyism that gets ahold of some people in this hobby that makes them turn off even the most basic elements of common sense. Whether or not you want to use pure objectivity to pick your gear or not, I don't see how holding some of these feet to the fire to defend their extraordinary claims is a bad thing.