I once owned a LD DAC_I and a mkV.
Their construction looks pretty good, but is very annoying if you decide to take them apart, very cheaply made.
But it works and is durable.
The DAC_I was the better part of the two, but the mkV does sound pretty damn good with audio-gd discrete opamps (OPA-Earth).
The DAC_I sounds fine with the OPA_Earth modules as well, but doesn't improve nearly as much.
The USB input on the DAC_I is decent.