Ralph as seen the light and states his main reason for going down the Class D route is sound quality. I wonder if he also recognises that price is so much lower than his very costly OTL valve amps that he is unlikely to stay in business if he offers only these costly monsters!
I have a pair of his Class D monos and they are very good. How much better they are than a well-implements Purifi Eigentakt amp is less clear. I have both and both have proved excellent, and considerable better value than any of the other ss amps I've had in my system, even those costing double the price.
Ralph should really spend time developing his Class D range to include a stereo amp and an integrated, as his sole offering at present is the mono amps. More power would be attractive addition too for many buyers, either via a more powerful Class D module, or possibly less costly to develop, a bridgeable version of his existing one.
My only criticism of these mones is their lack of 12V triggers - so important with mono amps, particularly placed out of sight or tucked away close to the speakers.