So, you're saying that the chip doesn't share ANY characteristics between DACs, especially budget DACs- that's simply not true. The implementation of the chip on budget DACs doesn't vary that much, at least not enough to completely change the sound.
I assume you are referring to the Crack, correct? Very easy to build and the HD600s sound great on it. They weren't kidding when they named it "Crack"- can't get enough of it! No Speedball upgrade for now- maybe later.
That's my current setup- I enjoy it very much! However, only thing I have to compare it to is the µDac2 (not bad either). They are fairly easy to drive, though not as easy as my V-moda M-80s or my M50s.