Sat 08-Dec-12 11:31 PM | edited Sat 08-Dec-12 11:33 PM by hijazist
The D700 is in indeed a fantastic camera and so is the D300 for what it is. I am not sure what you mean by HDR ability of the D600, if you meant bracketing then the D700/D300 are much better in that regard since they have 9-shot bracketing feature. However, since I got the D600 I rarely bracket anymore because the DR is incredible and I can adjust shadows/highlights as I want and still get a natural look to the image.
In terms of features, the D600 does not offer much over the D700. In fact, many regard it as a downgrade in terms of manual controls, build quality, max shutter speed and AF performance. Where the D600 really shines is the sensor. IQ, DR and ISO performance is well ahead of most DSLRs in the market except the D800/D800E. The same goes for D300 vs. D600. Other features that I find an upgrade from a D700 is the dual card slots, 100% viewfinder and U1 U2 modes.
I found those advantages of the D600 crucial for my needs and did the upgrade from a D700. I mainly shoot night street photography and the D600 is amazing at that. What do you shoot mostly?
The D600 will also offer you the option to shoot in crop mode with excellent IQ due it's high MP count. The attached image is heavily cropped taken at ISO 12800 with minimum NR. The D600 is also much lighter and smaller than the D700/D300 so it will be convenient for you cruises/trips. When I need better grip and balance I just attach the MB-D14.
It's a brilliant camera in a compact package and I find it perfect for me, hope that helps