I bought both of them. I'm not real happy about the load of FanBoyCr@p added to the sets, thereby making them so expensive. I bought the sets for the Blu-rays, and the extra audio/video material...
The "resolution" of the Blu-ray tracks is 24/96. While I haven't compared the DSOTM Blu-ray to the SACD, I can't imagine the SACD being topped.
I will be getting the WYWH SACD, in part so I can compare it to the Blu-ray. Again, I don't expect the SACD to be topped.
The extra audio in both sets is great. It's stuff that could have (and should have) been released years ago. At least I get to upgrade some of the stuff I have as bootlegs. The books are also nice. The packaging is terrible, along with the inclusion of drink mats, scarfs, and marbles. They could have left all that nonsense out of the DSOTM set, and instead added the original posters & stickers.