It's intriguing but I'd rather try and track down a copy of the 5.1 recording (30th edition) than buy the box set. Then I could do a comparison of that 5.1 to the original stereo version I have on CD. I think this is for hard core completists and collectors.
I will say this, I did get the Animals Remix and I've really enjoyed the remastered version. It's a clean, second pressing that didn't have the 1st pressing vinyl issues I had read about.
Now...I AM interested in that colored vinyl box set of Stones Mono lps. But a few reviews said they're not as revealing as the black vinyl mono box set that came out a while back.