I just got mine. I give it a thumbs up, although the only things I've had to compare it to are the internal DACs of the receivers and Pre/Pros that I've had. I'm now listening to the best quality music I've ever heard in my home.
Ignorance is bliss, since I don't know any better.
In any case, I'm using mine as a pre amp for all of my digital sources, to include a CD player, DVD, Apple TV and Sonos. It works fine, very fine, as a pre amp.
My only gripe, if I can call it that, is that the minimum volume is maybe a little too loud. It goes from nothing right to a low listening level, that may not be low enough for night time listening when everyone else is asleep. Still, the previous concerns of not having enough control over the volume have been remedied. The volume control is not unlike that of an infinitely variable knob. You can hold the volume button down and the level increases on a very gradual slope.
I like it and I think I'll keep it for now.