I just received a Quicksilver Head Amp, and my very early impressions are super positive. So far, I can't find anything I don't like about the sound, nothing that I would suspect might start bothering me after the initial new toy glow wears off.
It's quiet, sufficiently powerful, very easy on the ears while still being lively and transparent, and has a lovely tonality. All the frequency ranges come through well controlled and beautiful.
I just listened to a Bach solo violin sonata, and the violin's various tonal characteristics all came through in spades, and just so listenable. I usually go back and forth between a new amp and one with which I'm already familiar, to compare, but find myself not wanting (or needing) to do that here.
Very happy.