[ruined]

past f8 on full frame (and wider on smaller frames) you run into diffraction, so you actually do get more detail with a slightly wider aperture. i only glanced at the links but it seems about right.

also, everyone knows what a face looks like

[foldr]

Sure, but why not shoot a subject at infinity? (I said "wide aperture closeups".) It's hard to even know which tiny part of the face is actually in perfect focus. And at the resolutions tested, you will need perfect focus to see any difference.