http://www.camerastuffreview.com/en/component/content/article/344-canon-5d-mk3-testQuoteThe usable dynamic range of a Canon 5D MK3 RAW file at ISO 100 is up to 2 stops larger than of a 5D MK2 file. That is a big difference. In practice we found that the correct exposure in bright sunlight with the 5D MK3 was much easier than with the Canon 5D MK2. On both sides of the histogram, we always had 'space' left, which is the way it should be!
Two stops better at 100 ISO than the 5D Mk II - that's frickin' good.
That would be absolutely awesome, however, nobody else has seen that. Nobody else has measured that. And nobody else has measured the 13 stops for the 5D2/5D3 they got either, that's even higher than the engineer DR measurements and you can't get any higher than engineering DR. Conclusion is that they have no idea what they doing.
And if they always had space left on either side of the histogram then they were not shooting scenes with very high dynamic range for their real world shot tests, which also points the fact that they don't know what they are doing when it comes to talking about DR.
Praise it away for having apparently awesome AF, a solid fps now, no aliasing/moire, nicer looking high iso noise, outlined histogram, faster trigger, shorter mirror blackout, etc. but no need to push links posting nonsense about things so it can 'be' the best at everything, especially one of the aspects where it actually is most behind.