I've had my D4 about a month now and like it. I came from a D3, not a D3S.
>- Skin tones and color depth seem much better on D4 compared >to D3s, especially at higher ISOs like 3200. In fact, skin >tones are downright beautiful...
They look good to me. I'm not a great judge of skin tones.
> >- White balance appears to be more accurate in my estimation.
I generally use auto WB and it frequently requires adjustment in LR. I don't use NX.
> >- Not enough info to truly gauge high ISO compared to D3s, >although I’m getting some gorgeous crisp images with wonderful >color fidelity at high ISOs. At the very least, I’d say they >are comparable – although the slightly better DR, better color >depth and better skin tones (not to mention extra MP) puts the >clear advantage in the D4 corner IMHO.
I shot an event recently using ISO's of 6400 up. LR handled the noise well. I was able to get good images up to HI-1, usable images up to HI-2. Of course YMMV. I got images from HI-4. I even got images from HI-4 when I couldn't see anything through the viewfinder. I won't go any further than that.
> >- Focus in low light and general autofocus accuracy and speed >– WOW! The D3s was stellar. The D4 is epic.
Yowza! My keeper rate has at least doubled (based on clear images, not composition).
> >- Backlit buttons. Don’t undersell this feature – especially >if you do low-light and/or night work. Re-worked virtual >horizon works great too!
No experience yet. Haven't done night work yet.
> >- Great ergonomics. D4 is more comfortable to hold and just >feels better. Will have to get used to new button layout, >although I like how easy it is to access some key AF features >and pix controls. Camera feels a touch lighter, but when it’s >this big to begin with (and you’ve got a Kirk L-Bracket on >it), it’s still honking big, lol.
My only complaint about the Kirk L-Bracket is that if you mount it tight to the camera you can't get your finger in to open the data ports. I have to leave a gap, which makes the camera slightly larger, which makes it just a bit harder to fit in my bag.
> >... And at least from where I’m sitting, the 16.2 MP >image quality doesn’t look too shabby either...
Although I don't do large prints and most of my images are computer or web only, they do look better. Maybe it's just because I know there's more data there than the screen can show me.