Very interesting lens, indeed.
But everybody compares it with the Nikkor 70-200 2.8 VR II. Me, I own the Nikkor 80-200 2.8 (last iteration model). No VR, no nano, but a superb lens! And it was, until now, the only real alternative for the big, heavy and expensive 70-200 VRII (I don't usually buy third-party lens).
Please don't forget to compare this new 70-200 4.0 with the 80-200 in your future review. After all, today, the 80-200 is still in Nikon's catalog.