For some " listening " reason, I cannot part with these.

Over the last few years I have been evaluating amplifiers from my collection, as I want to minimize my gear, locally. Unfortunately, I enjoy each and every one, for certain sq characteristics. This last week I have been evaluating two different samples of my MTX Soundcraftsmen A400, the non pro version. One has been vastly tweaked by me ( and it is vastly " cleaner " than the stock unit ). I know that these were, at one time, a patented designed switching power supply, created by Paul Rolfes, and supposedly later copied / duplicated by others. I have sold several amplifiers from my collection and still have more, but, there is something ( many a something ), that allows me to listen to these, time and time again, for extended periods of time. They do have that Hitachi MOSFET " color ", which I always liked ( different from my Bryston 4B and my Yammie P2200, both which I find I need to hold on to, as they are enjoyable ). I am hoping Ralph from Atma-Sphere, you would come on here, and tell me what I will hear and experience differently, using your new Class D mono block designs ( I did not want to invade the other thread of your amp ). I play tracks like Sheffield Lab’s " L’ Daddy ", the " Drum " tracks, and Tony Minasian's " Drums and Bells ", and I cannot imagine it getting any better than this. Over all of my other amplifiers, these are special ( the tweaked one ). Why ? BTW, I am an amp junkie, at a lower price than Jays Audio Lab, and all of my evaluations are using my system.