I've never heard anything from DCS, But I have a C2700 preamp with the DAC2 board in it feeding Mac mono blocks. I also have/had a Chord Dave in my system. What I can say is the Mac DAC2 is better then many may think for the money. It punches well up into the much more expensive DAC range. But the Dave did show its limitations quite easily. The Dave has much better resolution, separation of instruments and bigger, wider, deeper sound stage. Its quite apparent when switching between the two. doesn't take an audiophile to notice.
If the DCS is not apparent from the start its just not that good IMO. Regardless of price at the levels we are talking if its not immediately apparent send the DSC back its just not worth what they are asking IMO. DCS has fallen back on their laurels in recent years from what I read, in my limited opinion of course.
Last note; new mac sound is not old mac sound, its not warm and mushy as people seem to think, and have commented on.