I have the Reuss as well, it is an exceptional DAC. I have compared it to the DAC1 Mk1, in my system, and I do prefer the Reuss. I am also considering an upgrade to the MkII, interested if anyone has done this or has general comments on the MkII.
Sounds like it was a close second in mitch2's https://forum.audiogon.com/discussions/six-dac-comparison