I have just gotten the D600 and like the buttons to limit inadvertant movement of the exposure mode selection control dial. I almost got rid of the D7000 purely because the mode changes by being bumped. There is a new button on the D600 on top of the dial. This button must be depressed to turn the exposure mode. No more unintended changes.
Now the dial right below it to change from Single to CL to CH and Mirror Up may be worse. There is a button for that dial and it is very hard to change settings while pressing the dial. I find you have to turn the camera around and use your right hand. It is very difficult to change.