oh!  and one last thing: the point isn't just that one might want that level of lighting overall.  it's that you might want that level of lighting _anywhere_ in your image.  remember the person saying their work looked "flat" after applying GC?  well, imho, the 3rd row looks much less flat.  this is one of the images you posted to prove your point about the realism of GC.  at the time, i thought how much less interesting and flatter the GC version looked.  you might show the difference with your new calculation.  maybe i'm wrong, and it won't be better, but i think it will be.

edited for cross post:  i see a significant difference by 15%.  and by significant i mean, if i were going for column 3, i'd spend days trying to get there from column 2.