Interesting. I like the 'sparkle' that Luxman has. Although I rarely listen to 'heavy' rock and roll, when I do, I have found some amps to be dull sounding. The Luxman sounds wonderful with every type of music, is what I am trying to say.
As for the OP - I don't think the Ayre DAC is going to be better then the Mytek. I have yet to hear a 'built-in" DAC that sounds as good as a stand alone one.