I'd prefer the D4 sensor in a D800 body and a D3200 sensor in a D4 body. However, I made a strategic error waiting almost two years for the D700S that never came. So lesson learned, I bought the D4 as soon as it was available. More body than I need for Theatre but right sensor. Certainly not a bad camera though!
Same with D7K, I wanted the sensor, so I bought the body. Doesn't have the buffer I need and frame right I'd like nor the advanced AF. But I muddle through.
My pattern seems to be to get the sensor I need above all else. Then I adapt on batteries, chargers, cards (shooting XQD, CF, and SD) and ergonomics. I recognize other's don't share this approach, but I trade off everything if the sensor has what I need.
The D600 small size of AF area as compared to FX frame area is a deal-breaker for most uses for me. That means a D600 would only have one ideal usage for me - travel - but that's not enough on it's own to swing me.
Next up I hope anyways is D800E, again for the sensor but the 4fps will be a limiting factor for one use I have planned - birding. I'm trying to sell the D700 and grip but getting zero interest so far, so I may put this off. From an ideal perspective I'd prefer a D4X with the D800E sensor and 8fps. But then I'd need the 800mm lens to go with, and that is a serious couple purchases
It's a tough one, this business of getting the right camera.