Sorry the only reason i chimed in was to bring in the correlation of higher megapixel aps-c not necessarily being a bad thing, if anything its a testing ground for the next set off FF sensors for each manufacturer.
The D800 has the same density as a 18 MP APS-C and its performance is stellar. The new generation 24MP aps-c's dont seem too bad either, but will require refined glass much like the 7D did.
Green tint on the D4 no, even my left focus array wasn't a problem.
D800 on the other hand, I got re-calibrated for left focus points being out and I got the workshop to custom calibrate the LCD (definitely green). Luckily in the city I live in we have a Nikon repair shop so its a same day procedure.
I personally dislike the size of the D600 - the camera and the images are nice but I can't physically hold the unit cause its just too darn small.
But that could be said about all Nikon bodies as I find the D4 just a touch too small in comparison to my old 1DX - that grip was perfect for my hand.
No reason at all to be sorry!
Regarding the green tint of the LCD, what caused that?
It's interesting you mention the size of the Nikon D600 being too small. I didn't realize it was much different than the 800. That said, I find the 800 (and 700) too big...or rather, the reach out to the shutter button, seems like it is perched out on a ledge a long ways ahead of the front of, say a 50mm lens. It's probably not actually that far, but it feels it. I wear a size 10 glove, my fingers aren't overly stubby, but it does feel like you need 6 inch long fingers to get the right grip, on Nikon's grip. By contrast, all of Canon's bodies feel like the same fit in my hand, going from XXD series to 1 series. I notice the increased size and weight of the body, but the grip feels the same. I enjoy the grip, and it's odd how after a while, it feels like you're not holding anything in your hand.
I also think the size of the control dial on the back of the D800 is silly. It's not much bigger than my finger...at least Canon's dial is the right size. I wouldn't want to get used to that.
Nikon seem committed to these ergonomics, so I don't see myself ever using one. I also don't like their lens lineup as much as Canon's, nor do I like the fact that many of their non-super-telephoto lenses, are priced above a similar lens offered from Canon, yet are sometimes an older design, that can even be inferior in some ways. The Nikon 135 f/2, is the best example.
All of that said, I still like what Nikon was able to achieve with the D800. When it first came out, I was trying to decide how much I wanted one, and if I was willing to sell my Canon lenses. It turns out the choice to stay with Canon wasn't very difficult at all, for me. For anyone (like yourself) who likes the D800 more than Canon, I can certainly understand why you would switch! It sounds like you're putting it to good use...no doubt better use than I'm able to do with my photography at the present. I don't blame Canon for this at all though, it's only myself.
No idea what caused the green tint - nikon doesn't officially say it's an issue, the stand that nikon takes is the cameras meters are the most sensitive to date and the wb is more accurate then previous models - I have sat with nps(cps) on so many occasions - unofficially - they have confirmed there is a beta firmware in the works which I will get my dirty hands on to test soon enough that is meant to fix this problem that isn't a problem lol!
I never found the shutter release positioning to be awkward surprisingly - its actually more comfortable on the D4 (enhanced ergos) - I used to miss the control wheel off my canon but tbh the layout on the d800 makes more sense then the d4 in terms of fec control is in an awkward place on the d4 - albeit its in the same spot on the Canon 1 series anyway - on the d800 its instantly accessible with your left index as it hugs the camera body left of the lens mount
Nikon does need to get rid of that ridiculous D-Pad - they copied canons joystick and improved on it with "click to EL" but then duplicates the controls on the D-Pad, I have asked that each direction become programmable but i suspect that's too much of an ask.
I initially hated nikons lens line up - I refused to believe anything could be better then my old L glass - I really missed my 300 f4 IS (I never needed a f2.
but I honestly love my 24-70 2.8G (spanks both MK I copies I had on canon) the 70-200 VR II is excellent and but I feel it doesn't quite match the IS MK II in terms of VR - the nikons is better balanced in hand but its about half an inch longer so just a touch harder to pack. I love my 85 1.8G and my 50 1.8G - I miss my 85 1.2L but the 1.8 trilogy from nikon is superb - out resolves nearly all the 1.4 glass on either brand. Regard to the 135 f2 - yes the canon is gorgeous - no question, but I actually rather like the 135 f2 DC - its a very unique lens the defocus control is "interesting".
I still have my canon film bodies - I'll never give them up
but at the end of the day they are all just recording devices - It's just what works better for what you do
On a side note - if you pick up a d600, d800 or d4 vs their older bodies - the vf markings and controls are Canonesque - by default... older nikon shooters have to revert to non factory settings if they want to use the unit how they always have - for example: how they are used too where the light meter is + 0 - not - 0 + (and seriously it makes no sense being + 0 - right?
) they even allowed for easy ec via thumb controls ala canon. It's as if they built these units with the mindset of allowing for the transitions between the brands. Outside of the missing wheel it felt like second nature for me - honestly. Pick up a D700 and it's all backwards.