I just reviewed HDVD800 (but you would need google translate, at least check the photos I took).
Long story short, I really like it paired with a balanced HD800. It needs a lot of burn-in to sound right, but when burn-in period passes HD800 just sings with it. I didnt use 24bit material for this review, so I didnt notice any issues with this unit. HDVD800 sounds great to me, unfortunately not as good with Audezes or other low impedance headphones, so its not quite an universal combo DAC/Amp.
Thanks for your nice review!
Do you know which chip or transistor is under the heatsink?