Alex,
"I shall compare the CD to SACD layers .."
I don't think you'll find much difference if you do this.
My experience tells me so.
You need to compare the hybrid SACD (either the CD layer or SACD layer) to the earlier version(s).
If you send me the SACD, I will make the comparison .
John,
I tried doing this with Bernstein's 1963 NYPO M2 on the Japanese SACD release, and also found hardly any difference between the SACD and CD layers. Also, in comparing the CD layer of the Japanese SACD/CD to the CD-only produced Carnegie Hall release of the same M2 performance in that set of the complete symphonies, I heard no difference.
That led me to compare the SACD layer to the CD layer of the recently-purchased Fischer/Budapest recording, and I also couldn't tell much difference.
So maybe we all need to ask ourselves: Is it worth bothering to listen to the CD layer of an SACD/CD hybrid disk to see if there's any difference? My hypothesis is that you will be able to tell little, if any difference on the average stereo system. On audiophile-grade equipment, yes. It would be interesting to hear from others on this subject.
Wade