A little late to the party, but in case this helps others with the same question (I know I did):
With Stax headphones, I found the Chord Dave with the mScaler excelled in detail, however the dCS Bartok was more accurate from a tonality perspective. In terms of soundstage depth, the Chord was more explicit (you could hear every tiny reverb in the room), whereas the dCS was more implicit and, maybe, more natural and relaxed as a result.
Both are at the top of their game. Which you prefer is likely to be down to personal taste.