If I understand the general conclusion in the "Audio 101 Part Three: Amplifiers" article, it seems to me that you are saying that class-D amps are really the state of the art, and that older class-A and -AB designs are not really as good. Am I missing something?
Class-D amplifiers are state of the art in terms of efficiency, and they can certainly sound quite good. But I'm not ready to say that they are state of the art in terms of sound quality. For the very best sound, I still think more conventional designs have the edge, even if they are less efficient, cost more, and are physically larger. Ultimately, though, you could build a great audio system around any number of amplifier configurations, no matter which letter of the alphabet your amplifier type ends in. . . . Jeff Fritz