Having examined Michael's second, updated comparison of shots of a $20 bill after both have been sharpened, I'm beginning to think the resolution differences between the D800 and the D800E really are too small to be worth bothering about.
The differences in the unsharpened images are sufficiently great to become a concern, but appropriate sharpening seems to have narrowed the differences to a point where one really wonders under what circumstances, outside of extreme pixel-peeping, such differences would be apparent.
Can I suggest the following test. Michael should make a 24"x36" print from the D800E shot, according to his satisfaction, then ask Jeff Schewe to make another print from the D800 RAW image of the same scene, using the same paper, ink, printer and profile etc, with the request that Jeff try to make the D800 print look as close as possible in quality, sharpness, color and contrast etc to the D800E print which Michael has previously produced.
Both prints should then be circulated to experienced photographers in a double-blind test to see if they can correctly identify which is which.
If most of the viewers are able to see the differences when holding the prints in their hands and viewing them from the close distance one might read a book, the prints should then be placed on a wall, side by side, and viewed from a more sensible distance equal to the diagonal of the print. If the differences can still be correctly identified in that situation, then I think there's no doubt that the D800E is a worthwhile improvement.
However, I'm still uncertain about the noise implications of sharpening under certain circumstances. Is it likely that deep shadows in a D800E shot will be noticeably cleaner as a result of the lower sharpening required?
When the images are shot at a high ISO where noise may be almost unacceptable, will the differences between the two cameras then be more noticeable, the D800E shot being either noticeably sharper or noticeably less noisy?