Nikon fanboy Moose Peterson was "blown away by both":
D3s & 70-200VR II Just not what I expected! : Moose News Blog
"In my mind, ISO 1600 is like ISO 400 or less on the D3. ISO 6400 on the D3s is like 1600 on the D3."
Yeah.... well... I doubt that. But it looks good nonetheless.
Why not use your own eyes and look at the photos smart guy? You know, photos from somebody who actually HELD and actually SHOT the new camera AND the new lens and wrote, after his tests, "The D3S at ISO12800 is comparable to the D3 ISO3200 and the D3S at ISO25600 or HI 1 looks cleaner and more pleasant than the D3 at ISO6400. D3S users will effectively gain two additional stops of usable ISO performance. The result astounded me and dispelled my initial skepticism. ISO25600 or HI 1 on a D3S is the highest I would go for my wedding work."
Or maybe stop by the links provided and see what Rob Galbraith wrote:
"The high ISO image quality improvements in the D3S are real, and they're substantial. Based on what we shot that evening it's safe to expect at least a one stop improvement, maybe more. In other words, overall image quality at ISO 6400 on the D3S is at least as good as ISO 3200 on the D3. And perhaps better, as you'll notice if you look at the photos we shot with both cameras at ISO 1600 and up."
So, we have three established professionals, two of whom claim a two-stop improvement in high ISO performance, and another who claims "at least a stop improvement, maybe more". And we have MrLogic disputing the claims all three people publicly made based on...nothing...