I adjusted my red by 2 for full screen. I did this full screen. I have read that using this should be moderated as it does effect (somehow - don't ask me) resolution or brightness to some small degree. The visual effect is what you would expect. It removed the red fringing on a white cross grid pattern I was using to set convergence. It made computer text and the like more focused and crisp. There is some info posted elsewhere by Mark Haflich (maybe in the shootout thread?) on its usage. He recommended full screen adjustments if possible over the zone adjustments due to the side effects they cause. Visually however, it is clear the adjustment was for the better in my case.
I did not try the zone adjustment - sorry guess I did not really reply to your question very well.