Techradar got a full-production sample of the EOS-1D X and have run it through their labs. The hands-on review they made includes resolution charts, dynamic range and signal to noise ratio. They’ve compared the 1D-X with the Nikon D4, but also the EOS 5D Mark III, the EOS-1D Mark IV and the Nikon D800.
Sample images are provided too. Btw, I heard from various sources that the major shops are starting to stock EOS 1D-Xs.
EOS 1D-X price check and availability: Amazon, B&H, Adorama, Canon USA, Digitalrev, eBay. The following seller should have the 1D-X for $6,799.00 (click on the shop name): Adorama (click here), B&H (click here), Amazon US (click here) and DigitalRev (click here).