Redbook Quality on Hybrid SACD's

I think there is some variation here. Yes, there was a recent thread on AA Hi-Res about this. In any event, although I am still out to lunch on this topic even after reading all the posting, I can confirm that some CD layers on SACD hybrids sound better than their redbook only predecessors (Tommy, some of the Stones, etc) and, some are a disappointment (Elton John GBYBR for example).

I don't think there is consistency here.

I too found that the Redbook layer of a Hybrid SACD is usually better than its regular CD equivalent (about 70% of the times). However, I would have to agree with Rcprince. Unless the original recording has been remastered for SACD production, chances are that the two CD versions are the same sonically.
I've owned some classical recordings that were produced and released on CD in early to mid-90's. When I played the Redbook layers on the Hybrid SACD's of these same (but remastered) recordings, I hear a noticeable difference, mainly a more balanced and focused sound. Could this be due to a better CD mastering process (XRCD comes to mind)? I don't know the answer...

redbook layer of Hybrid SACD is definitely sounds better than normal CD. However, this layer still cannot compete sonic with SACD layer in SACD player, even if you put redbook layer into decent player at 10 times price of SACD player.

I did detail testing on this issue, software I tried:

Kenny G Live
Norah Jones - dark blue cover (cant remember title)
Aaron Neville - Natural Boy

A similar question raised recently on the SACD forum at AA. The response I find best is from Michael Bishop of Telarc, who says that unless there was a different master used for the CD version (which could indeed happen), it should (and at Telarc, at least, is) the same disc whether CD or the CD layer of a hybrid disc.

In general the redbook quality of a Hybrid SACD seems better that the redbook quality of a standard CD.
So I would say IMO the odds are slim the redbook layer will be worse than the standard cd. It should be at least as good, with a reasonable chance that its even better !