Obviously there is a vested interset in a Class D amp and some are not open to what the best amp makers are saying:)!
I don't think GC builds & sells class D amps in his spare time... really.
Just as an idea: listen to a couple. I did. I wasn't enthused by the sound. OTOH it wasn't really bad, just not as good as my amps (which also cost 11x more).