Canon EOS 1D X Mark II vs 1D X: What's new?

In 2016 it's the year of the pro DSLR once again: the Canon EOS 1D X Mark II follows hot on the heels of the Nikon D5, which was announced a month earlier at CES 2016, but how does this full-frame pro-spec DSLR compare to its 1D X original? We handled...