Redbook layer on SACD - good enough?

KR4-I have the new Miles Davis box set The Complete Jack Johnson-it was mastered using the DSD process but it is NOT a SACD nor hybrid.
So if the information on this is correct then the DSD process can be used to make CD's as well as SACD's.

It's been my experience with hybrids that the mixes are identical on the different layers-it's just the actual replay formats that are different.
As such any difference is down to the superiority or otherwise of the format.
I've found the Redbook remastering all recent hybrid SACD's with the exception of DSOM to easily beat their previous incarnations on CD.

In addition to all his other comment with which I concur, Ben Campbell wrote: "So if the information on this is correct then the DSD process can be used to make CD's as well as SACD's."

Only if it is converted to PCM as it usually is. I was questioning 'lafish' saying that he had played DSD on his CDP.

What about Aroc's comment:"The cd pickup (780 nm) would have to read through the transparent layer designed for the 650 nm SACD pickup"?
No matter what, SACD layer cannot affect focusing, whatever, of CD layer?