in my experience with the bog harbeths i liked an amp with both strong bass damping factor/grip and also a little extra treble energy as the speakers tend to be a little midrange and bass rich in tonality
so, for example, i preferred hegel 590 over 390, i preferred pass class a/b over class a, belles class a over sugden, classe over primare, you get the picture...
for this reason, i would probably choose the luxman for this application over the accuphase as the accuphase has voicing that is rather duplicative to the harbeth sonic traits