Anyone have experience with Chord DAVE vs dCS Rossini or Bartok

I would appreciate comments and comparisons between the Chord DAVE and either the dCS Bartok or Rossini, especially from anyone using these DACs in a tube (rather than solid state) system.
Thank you.
I had a Bartok in on trade and am a Chord Dealer.  My feeling was the Bartok bested the Dave in terms of imaging slightly and was about a push in terms of detail.  Adding the MScaler took the Dave to the next level and it leapfrogged the Bartok.  

I am not sure the Dave MScaler combos would be a push vs. the Rossini or if the Rossini would be superior.  

What I would bet is that all of them are a step down from the Playback Designs MPD-8 Dream DAC.  

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.