I have not heard the MkI but the MkII sounds very good (Tkam's). Good frequency range, and very good soundstage. Heck, I did a side-by-side it to the burmi 006 DAC and yes, the burmi is better in all respects, but the northstar is no slouch, specially in soundstaging. I used the XLR and the BelCanto CD2 as transport for both.
I am not going to keep it as I decided to not assemble that other system (Bel Canto CD2/to a DAC), in other words I already put the transport up for sale on A'gon. So let me know if you are interested in the DAC. I'd let it go for $950 shipped!