Well I just got the E after a few months and a lot of shooting with the D800. Its different alright and I can only speak in C1 but you may want to take this to LR as well. Immediate visual difference the E is certainly sharper looking coming in at default and you know what they say about default , Its wrong and 9 times out of 10 it will always be wrong. LOL
Honestly i dont care what program your in you need to make a new default, preset or style for this cam. In C1 its too sharp and I have lowered my sharpening from 240 to 125 from the Non E to the E. but that was just a start it also has too much mid range contrast in the clarity. On the non E i added 15 points on the E i actually dropped it down to -15. Now let me stop right there as people that are looking for a look in there files as smooth than this is the ticket right here. Clarity is way to high coming in. So C1 and LR users you need to go play with this and drop the clarity down and do some side by sides with it at a lower setting. It smoothed the file right up. Also its a touch more contrasty too so I dropped it 5 points and than opened the shadows 4 points. Now I have my new default for the E . Now i can make a style in C1 to apply on import or you can make a preset in LR as well and apply this on import. Very important to get your base level down.
As Jack has mentioned which I do agree we can get a file to look identical with the non E and the E that is very clear now as I have the E in my hands. It just depends if you like going up with your settings or reducing them down. I tend to like reducing things down so maybe the E is better for me and yes end of day the E may have that slight micro detail advantage but you may never see it in print either. I will warn you out of the gate you start taking the E down in either program you think you are reducing the quality of your images because its not so sharp but reality is your getting them down to a better looking file. Natural for people to over sharpen digital images and it will look digital to get a smooth palette you need to drop this cam down some.
Now don't get me wrong either cam you can get to look like the other cam with the correct processing routine. Its a very very slight difference between them and end of day still not sure the E is the ticket over the D800. Maybe if you dont like to tweak things out of the camera the E will certainly look sharper. Myself I am after a look so whatever it takes to get that I have no issues of dropping sharpness and clarity levels to get it. Honestly the E looks a little too brittle ( subjective) coming out of the cam.