@magon How are you getting on with the MHA200 by now? I wanted to love that amp but felt pretty much how you described it, pretty flat sounding. Also I don't think it has enough guts for more difficult loads. It does sound pretty in a way though.
I much much prefer the big MHA100 and nearly identical MHA150. I know, very different animals as those are integrated speaker amps with onboard DAC and headphone outputs. But they do seem designed primarily with headphones in mind, and the speaker outputs are more of a bonus. Most integrated amps are the other way around.