Okay, I’m going let it out of the bag right now. The new Nikon 70-200mm F4 is fantastic! I have now been shooting this lens for a few weeks, shot everything from indoor basketball games in low light to stomping bison in Yellowstone, and I have been very impressed.
I base my evaluation on field use. There are a number of reviews out there that test the lens using resolution and color charts, and these for the most part support what I found out. This lens is tack sharp, has minimal vignette issues, and uses Nikon lastest (the only lens to do so) VR technology. Why would I ever want to use this lens instead of my trusty 70-200mm 2.8? Two reasons, size and weight.
As you can see from this picture, the lens is significantly smaller and weighs 1.8 pounds, a pound and half less than the 2.8 version. This is my new travel and landscape 70-200mm, and a great buy for those who don’t need 2.8 glass….the lens costs a thousand dollars less, around $1400.
One point reviewers have made is this lens won’t focus as fast as the 2.8 version. I tried out my D4 and 70-200mm F4 shooting my son’s basketball team yesterday, think low light gymnasium. The lens focused quickly without a hitch. It makes sense the 2.8 version will focus better in a very low light situation, and this might be a concern for some shooters. 
In terms of sharpness, other reviewers have noted that this lens is almost as sharp as the 2.8 version. I have found it to be razor sharp. The top Teton shot was done with a D800 and this lens, and at 100 percent on the big screen I can see amazing detail in the tiny trees on the mountain. Sharpness…check! This lens has 67mm front, which will require a smaller polarizer than my standard 77mm front on my other lenses.
If you are in the market for a tack sharp 70-200mm Nikon lens, and don’t need the extra 2.8 glass, consider this lens. It is a lightweight, tack sharp option that will be in my pack on many photo shoots and workshops.