Quick update: I've shot quite a bit with the fine tune set from -17 to -20, and I'm getting sharp results at all focal lengths and apertures. Since this is considered by Nikon to be within spec, I probably won't fuss with it - interesting that I have the same result with the Sigma 24-70/2.8 EX.

Sample after AF Fine tune:



Focus point was the right of the dog's throat, just under the jaw, where the fur is going from white to black, verified in CaptureNX2, taken with AF at -20.


Sample before AF Fine tune:



In this sample, focus point was the right side of the dog's muzzle, from the nose to just under the eye, verified in CaptureNX2, AF at 0.

I'll probably do more boring test stuff with rulers and such, I have a hunch based on a few from today that -20 is too much, and I should be around -18.

Anyhow, I'm liking the lens a lot, see a lot of potential, and now just have to learn how to use it.