Ron,
Sorry to say, but your analysis suffers from the most profound anti-digital bias - listening to digital through the analog perspective. It shows from the choice of the recording and from the methodology.
I am the first to say that if I listened only to 60's recordings I would listen in vinyl or tape. These recordings were recorded and mastered to sound good in vinyl, by great experts that knew about the limitations of the media an use them to their benefit. It is a joy that today great systems allow them to show their full quality for our enjoyment. But they will never allow digital to show its best.
And sorry to say, saying that "
the LP was at least slightly more transparent in the voice (I thought it was significantly more transparent in the voice) and significantly more realistic in reproducing the sound of piano" when we can't be sure if both recordings come from the same masters is meaningless. Since long it is known that this type of comparisons - isolated LP versus CD - are misleading.
IMHO when you say that "
Alex then played a high-resolution remastering of “After the Goldrush” and the LP’s margin of superiority narrowed considerably you say it all - IMHO you were also listening to mastering differences.
I do not have fears of any media besting any other. I know that there is enough space in the grey area of stereo reproduction - that area that must be filled by our experience and preferences - to be sure that we can pick any one as our winner. Fortunately in this case we are is the jury and judge.
The only test analog people can fear is someone recording in DXD or DSD2 the output of their great vinyl source and showing that they can not separate the source from the original in the long term - but this is very improbable to happen.
Anyway, thanks, I am really enjoying your writings on Alex great room and system!