Consolidate/sell my headphone system for a DCS Bartok?

I'm afraid I would have to disagree about the PS Audio being "mushy and reserved", I find it anything but. This makes me beg the question are you keeping the DAC software up to date as we are now on "Windom". If you have been updating then I apologise and would offer another suggestion of , have you thought of silver cables in and out of the DAC. A couple of years ago I started off with a new USB cable which was the Tellurium silver cable and it made a startling difference to my sound but not at the beginning. When I tried it at first it was very forward with a definite treble imbalance. It took a long time to break it in ( about three weeks with a big hard drive playing all day and only switched off at bedtime ) but it sounds superb now. After that I Then replaced the balanced cables from my DAC to my headphone amp and that was another big improvement. I am of the opinion that your headphone amp would maybe best the headphone out from the Bartok as these headphone amps are truly made for the  purpose of amplifying a signal for the sole purpose of headphones. 

erik: Actually I have not heard the Ayre. I had an AX-5 Twenty for a while which I really loved but had a really bad damping factor mismatch with my Focal speakers. I might give them another look as I like the sound of their analog gear and their digital filters.

jim: I’ve actually pushed the Directstream pretty far: I’m on Windom, I’ve got a Synergistic Orange Quantum fuse in their, IsoAcoustic Orea feet, Wireworld Eclipse 8 RCA. For input I’m currently going from Mac (Audirvana) with a Shunyata Sigma USB to Matrix X-SPDIF2 with Uptone LPS 1.2 power supply and silver DC cable, and then Wireworld HDMI into the I2S input, so actually there is a fair amount of silver in this setup. The only improvement at this point would be the Innuos server. I’d love to use balanced cables, but none of these HP amps are balanced.

In all fairness, the DS was out in the cold for a while and it’s been on less than 24 hours. I had a problem with video board and had to send it in for repair and was listening to my Mytek Manhattan II in the meantime, which I got used to. I have some issues with the Mytek (it’s a bit thin), but when the PS Audio finally came back I noticed the width was narrower, everything was a bit too soft and smooth, and the DAC was less lively/punchy and expansive than the Mytek with the Apodizing or Hybrid (min phase apodizing) selected.

Ian, Forgive me about Grans and Sucking eggs but have you inverted the phase on the DS a few times to see if that made a difference.

What does that do? 

I've inverted the phase and back before, but I just left it at "In" which seemed ok.

Ianb52 Have you listened to the Bartok in a system or any of the DCS components  ? ...I think your wishing your PS Audio , King or MZ3 or even some other combination would equal or beat the DCS , the Bartok is in totally different level of performance over the PS Audio dac including many other middle of the road components like this. It has little to do with the price differences over other one box much more affordable components and or combinations of like your thoughts.
As you must be well aware $20,000.00 for the Bartok is a pretty big step from your current components , the Bartok being a single box solution you should have not purchased the Innuos streamer /server 
Something else to consider with a purchase of a component like the Bartok are other components plugged into it should be of equal sonic merit and most importantly a choice library of much as you can well recorded uncompressed music .

Finally you may also consider a Innuos Phoenix to pair with your sone to arrive Innuos Zenith, that single component add on will definitely give a boost in performance with your current components.