Nikon D4s - Just a comment
I have been a bit busy, but I felt that I would be doing a disservice to people if I did not write something brief about the D4s.
If you have even thought about upgrading from the D4 to the D4s, do not wait. The D4s is nothing short of amazing when compared to the D4 as far as ACCURATE and FAST AUTO FOCUS, color accuracy, color depth, and straight to JPEG shooting. Yes, the 2.7 crop video is beautifully sharp as well. If you shoot primes like the 35, 58, 85, 200, do not walk, run to the nearest store and swap your D4 for the D4s. It is truly amazing. The focus locks on moving subjects and is dead on. This is the best auto focus that I have seen on any camera ever.
There are plenty of reviews out there from people who have merely unboxed the D4s and never shot with it. Those who have can't help but rave about it.
Example comments:
http://news.coreyrich.com/2014/03/ask-corey-is-the-nikon-d4s-noticeably-sharper-than-the-d4-in-fx-mode/