>All that said, the D800E is an incremental improvement over >the D600 and Nikon has always charged a premium for their top >of the line gear, so if he wants the 19% resolution increase, >(your image quality argument, I believe), then he will fork >out 50% more money. That is something to ponder.
The D800e has a number of additional/improved features over the d600 other than just more megapixels.
Some are not big deals IMHO: like the full magnesium body as opposed to just the top and bottom of the camera.
Others can be a huge deal, like:
A better, more advanced AF module with more cross type sensors; a max flash sync speed of 1/250 (as opposed to 1/200), a max shutter speed of 1/8000 as opposed to 1/4000 (at 1/4000 if you shoot f/1.4 lenses you won't be able to shoot wide open on sunny days), the ability to use faster CF cards and USB3, the ability to change aperture while in live view shooting video on the fly (the inability to do this on the d600 largely makes the video unusable unless you use a lens with an aperture ring), the cancelling of the LP filter eliminating the need for capture sharpening. There is of course the always debated ergonomics issue with the d800e have dials and buttons to change most shooting variables quickly whereas the d600 is largely menu driven.
Both the D600 and D800e are outstanding cameras, but the D800e is far more than just a D600 with more MPs. If one doesn't need these features then the cheaper priced D600 is incredible value. That being said, I think you get your monies worth with the D800e as well.