Noise reduction in 5Dmk3
depends on what do you mean by noise reduction.
it's well known that Canon cameras preserve more original raw information than Nikon but that doesn't necessary exclude the possibility they do it carefully so that people won't detect.
we used to have the black-dot issue with 5D2, which was solved by a firmware update. the black-dots could have been generated by similar smoothing algorithms found in Nikon cameras, but no negative effect of Nikon cameras have been found in CR2 images. I'd like someone tell me if there is good evidence Canon cook CR2 at low ISOs.