Previous century? So, our hearing acuity has surpassed the previous century acuity? Now we can hear below the threshold of detection?
Does it matter what was driving that amp? Or the speakers? After all, the only thing changed were the two amp/integrated. The golden ears, self proclaimed, could not differentiate and cheap integrated and a 5 figure monoblock.
I have no idea about all his other amps until they are tested in such a way. Probability is that they should be equivalent. So, in essence you are claiming that Nelson designs amps that may not be transparent? Would be interesting to see the specs on them all, how much they differ from each other in an audible way.
We are not talking about regrets, or preferences, only audible differences.