I've recently received the SMSL VMV D1 DAC via Massdrop. Sound quality is outstanding and was a clear step up from my NAD M51, Marantz SA-11S1, and Wadia 121.
With that said, it lacks a bit of operational refinement one would expect from a top tier component. It isn't bad, but that its simply evident they went for all out performance above all else and succeeded in that specific effort.
What I will say is that you must research the specific product as the design goals and results vary from product to product, which is of course to find as broad market as possible. Not all of the products have that specific performance parameter is a top priority, but instead a balance of priorities, which sometimes can be cost.
But damn did they make a good sounding DAC in the D1.