I disagree. The USB option is convenient and for a lot of folks indeed represents an upgrade but it falls far short in terms of delivering for the audio enthusiast. This product I believe is aimed at a different market from the original and indeed many DAC's - this is aimed at people with an investment in modern digital audio (digital libraries, some nice headphone a shiny macbook etc), not as previous generations have been - aimed squarely at the hifi market. So for many people happy with a small improvement in sound (ie the majority of casual listeners) USB does the trick though its not really for serious hifi use and I think CA know this (it says as much in the configuration section of the manual and online).
I think they could have done a lot better here and it is disappointing that even after this long they failed to produce something decent over USB. Your right the Chinese can pump out better for considerably less so why couldnt CA ?.
My concern here is that ok the poor input was covered to death...what about optical and coaxial properly setup and configured - this would surely be a game changer through the HS? When I had the original DM (Azur) it sounded horrible through USB and that all changed when I swapped over to Optical - my thinking is give it a go in either coax or optical and then give an opinion on sonic capabilities.
Finally for my money I wouldnt use USB on any DAC - its simply pants. When you need to buy USB to SPDIF converters you know something's not right.