High end vintage vs contemporary DAC's - are sonic improvements real?

The vintage DAC question seems to arise regularly, more or less along these lines:
     "I can get an old XYZ for $2000 or a new ABC for the same $$.  What to do?" 
The answer almost always seems to be "go with the new ABC, the XYZ is older technology," "digital has improved enormously," etc etc. 

Obviously digital technology HAS improved enormously in the last 20 years (or even 10 years, or the last week depending on your belief system).  Sampling rates have marched upwards (though many will say that anything over 24b/96khz is a waste, and I agree) and everything has gotten cheaper and smaller.  Music servers have evolved and storage is cheap.  We have streaming now and use phones as remote controls to manage infinitely large music collections.  The list goes on and on.  Yet in my mind it's really THIS stuff that's embedded in the assertion that "digital is much much better than it used to be."

But how many people have actually compared a high end DAC from, say, 1996 (now selling for $1500), with a new DAC for the same $$?  Sure, features won't be the same - the old unit won't have USB anything, higher sampling rates, etc.  Yet for all that, I can't recall any conversations on actual apples vs apples comparisons of new vs old, especially on the **same** source material, specifically on a Red Book CD or a lossless CD file rip.

Example: In 1992 the Mark Levinson No.30 DAC was sonically at the top of top for Red Book CD reproduction (feel free to substitute your favorite DAC of that era).  Fast forward to the present. How much better does today's DAC de jour sound playing that same CD?  Sure, source file X recorded and mastered at 24b/192khz will likely sound better than the same file downsampled to 16b/44.1khz when played on a decent system.   But will a Red Book CD played on a new DAC sound better than the same CD through that ML No.30? 

To be clear, this isn't about sampling rate or format wars.  Think of it like this:
Let's say I have 15,000 CD's, that's all I ever want to play, and I've $3000 to spend.   What would I get for the same $$ that would sonically do as well as the No.30 playing the same CD?  Is the answer "almost anything, because sonics have improved so much"?  Or maybe it's the $10k such-and-such.  Hopefully this illustrates the question.

Comments and thoughts would be greatly appreciated.