I have read through the past view years of comments on the topic and didn't see my question addressed.
The question of whether it is <<needed>> has been covered (with interesting comments about KR), but not whether it <<should be done>>. What's the difference? It might increase focus but create a pain in the a--. I write this because the D800 manual says, "AF tuning is not recommended in most situations and may interfere with normal focus; use only when required." So if Nikon doesn't recommend it, why? I assume people are not finding problems after AF fine-tuning, but I had to ask.