I have heard the ML NO.53 a couple of times,So have I, and the problems in the upper mids and tops while a bit different are there, they are also in similar way in all other class-D's I've heard.
I have not heard the Technics SE-R1 nor the Merrill Element 118, but the mids/highs areas of concern with Class-D that many hear, seem to be the areas they say they have addressed, which makes me very hopeful they are leading the way, to make Class-D hiend.