Nothing special -- just testing the 85mm 1.8G -- I am really pleased with the lack of high iso noise. I've just been shooting it with Auto-ISO on and it works perfectly. Big step up for me from the original Canon 5D.
If you have the money to invest in good glass and can afford to go FX right off the back then yes, I see no reason it wouldn't be a better option versus the D7000 or D5100. The D600 simply opens up more scenarios where you can shoot and achieve the image you're trying for.