>I understand there will be additional processsing work >necessary for a D800E image but can't find details.
I didn't notice anyone mentioning it, but it takes extra processOR time, in the sense that your favorite program may need to work harder. I use lightroom, and rendering 1:1 previews is noticably slower, maybe 3-4 times as slow. To be fair, I had to upgrade to a new version at the same time, so some of the slowness may be it.
But also when I render into Photoshop to edit from Lightroom, it's noticeably slower. Not unacceptably slow, but slower.
And of course for a given speed card, 3-4x the size image takes longer to download to your computer, or to upload to your photo web site.
So when people talk about extra processing time they may be simply talking computer time.
Most of this to me is moot -- I tend to come into the house, pop the CF card in the reader, start lightroom, and go clean up, eat, drink, etc. and when I'm done all the shots are loaded, previews built, etc.