OK...so I have compared the Sony K2HD CD version to the recent Analogue Productions Remaster. In a word, APO wins for me.
Honestly, the K2 is excellent, and if this were not probably in my top 5 jazz albums, I would be extremely happy with the K2. It is clear, dynamic and exceptionally detailed. I hear a lot more than I did on my old CD I got years ago where the signal came thru 'weakly'.
At the same volume, in comparison with the APO, I also initially was inclined to favour this clarity. Until I turned the knob up on the APO to the level where it 'felt' at about the same level as the K2 (volume 42 vs 32 on K2)...and then I realized I prefer the APO.
The difference? Both great, but the K2 feels like an exceptionally clear remaster of an old recording, with that slight edge of brittleness that comes (in a more extreme fashion) from Furtwangler recordings from the late 1930s. Again, the K2 fees like an exceptional remaster of an old recording.
By contrast the APO feels like an excellent remaster of a natural recording. Maybe note quite as natural as the Herbie Hancock Joni Letters CD, or a Norah Jones album...but close enough, I don't care to scrutinize.
I never scrutinized with the K2 either...but I was always conscious it felt a bit like an old recording. I will continue to listen to APO some more, but at the moment, I don't feel it sounds like an old recording anymore.