@mr_m, As you requested, I owned the Hypex NCore NC400 Class D Power Amplifier dual-mono blocks (2 NC400's per box) and the Mola-Mola Kaluga NC1200 Class D Power Amplifiers.
Based on my listening experience, with both the Hypex Class D amps and then the Mola Mola amps, I did not feel they sounded very musical in my system and environment. In other words, they did not sound natural and I had problems listening for long periods of time.
I asked several 'experienced' audio friends over for a listen and they agreed with my thinking. As I said in my above post, this is MY opinion and others may disagree. In fact, based on other Audiogon posts, I know that some people like Class D amplifiers. I do not like Class D amplifiers based on my listening experience with theses amplifiers. I hope this helps.
I then purchased the SimAudio 700i V2 integrated amplifier. My SimAudio 700i V2 amp sounds excellent. It sounds clearer with more musical detail, better bass and more. The sound quality of the SimAudio 700i amp was exactly what I was looking for.