PS Audio Directstream DAC?

Whether or not the market will be "flooded" with used DS Sr. first versions will depend on what PS Audio offers as a trade-in as opposed to the open market.  Like @blisshifi  I have and still own a modified DS Sr. and like he said it is a very good DAC to this day.  I also own the Aqua La Voce S3 which bested the DS both in original and modded condition.  If you can find one in the same price range or close that would be my first choice.  You can also look for a used or even new Holo Spring 3 or the new Gustard R26.  No experience with the Audio Mirror but it has a great reputation and following but PCM only if that matters. 

the second to last 'windom' firmware version is much more laid back and ’analog-sounding’ than the very last version called 'sunlight' which brought forward etched detail in a big way...

Can you download and try different firmware versions or only the most recent?

They should all be in the software archive on the PSA website

I think the used DS DAC is the audio steal of the decade. In my system it sounds wonderful. Vocals tonally realistic without any digital glare. With the right recordings the soundstage has depth and width. It also provides details without fatigue. I don’t use a preamp as it has a remote volume control.

This is comparable to other $6000 DACs and can easily be had for under half that. I haven’t heard the previous software revisions or the Edcor transformer upgrade but just having those as options to me only raises its value.