I find these specs entirely plausible, the 1DX just isn't an affordable proposition for most people unless you're a demanding pro with tons of business or an avid enthusiast with lots of disposable cash. It simply isn't on the radar for 98% of FF DSLR users.
The 5DIII NEEDS a spec sheet like this because, the advantages it once had i.e. 20+MP and great video are going to be standard for all the new bodies that occupy it's price range. The current 5DII falls pretty short against the D700 once you remove these 2 advantage. If Canon continues to cripple the 5 series, they will most certainly lose alot of new customers to Nikon. Why would someone who already needs to buy new glass in order to move up to FF pick the 5DIII over the D800 if the Nikon has superior af, fps and build quality for roughly the same price?
I think Canon realizes that the advantages it once had are now gone and it needs to step up it's game or risk losing the slew of crop body users who eventually plan to go FF.....
I for one hope the specs are true so instead of a 1DX, I could get a 5DIII + 24-70L + 35L for roughly the same price as a 1DX which would complete my FF kit.....