You wrote:
Yes, some superior SACD releases probably do exist, but they are most certainly above the usual DSD64/2.8MHz releases.
Please explain what that line is supposed to mean. Could be you're just not a very precise writer.
I guess, that I am probably asking too much of some readers. You do know that you are being pedantic, right?
DSD64 is roughly equivalent to a sample rate of 24-bit/88.2kHz PCM. Since SACDs are able to store an equivalent higher sample rate than CDs, the existence of a superior mastered SACD compared to the CD release is both possible and probable.
However, as the usual SACD DSD64/2.8MHz releases are highly contaminated with Red Book CD upsamples, one should expect a superior SACD to have a better frequency response due to being sourced from a higher resolution PCM master.
Whether or not a SACD release is sourced from low resolution PCM, needs to be verified, just as Archimago has attempted on his blog:
LIST: Suspected 44 or 48kHz PCM upsampled SACDs.
A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.
archimago.blogspot.com