Of course, one last thing to point out is that SACD & DVD-A are both just sound carriers, mediums for whatever content you store on them. If you master the disc using an inferior quality analog tape (I'm thinking of old tapes in poor repair, sometimes several generations removed from the master), that will not sound better than the original. And if you start w/ a 16 bit PCM master, that's as high a resolution as the SACD will have (there are SACDs w/pcm masters).
I recall that in the case of some of the one of the Police (or Floyd, sorry, can't remember) all the previous CD releases were made from "masters" that were poor copies of the original, which was lost. But recently the original was found and reissued.
The best sounding discs I've heard were either recorded in 24 bit or direct DSD, and I've heard some awesome recordings transferred from good quality analog masters.
Again, setting aside the issue of MC, SACD & DVD-A still sound better than redbook, even in stereo, although IMOHO, a well done MC version still trumps 2 ch.
