I cannot speak of very high power class D, but my Rowland 102 producing 150W with my 6 ohm speakers is wonderful at low volume. In spite of hearing curve I don't feel any lack of lows or highs, resolution is there and image is even better than one at higher volumes (that might be related to some echo in my room). It behaves much better at low volume than my 50W Cambridge integrated, I had before.
Also, I hear much less noise/hiss while bringing my ear to the tweeter, in spite of higher power.
Also, I hear much less noise/hiss while bringing my ear to the tweeter, in spite of higher power.