I still haven't received my D600, but the D7000 had the same Easy-ISO feature and I loved it. In P, A or S modes, one wheel always gave me direct control of ISO, that's great. I went as far as setting U2 to Manual mode with Auto-ISO on, so that between A, S and U2, on each of these I had the wheels setting two of the three exposure triangle variables, and the camera automatically selecting the remaining factor to achieve proper exposure.
As soon as my D600 lands, that's the first thing I'm gonna dial in. To me, this mode of operating beats touching an ISO button to select value anytime, never used that button.
http://egozarolho.blogspot.com 1. Good content, good aesthetics and good tecnique. On that order. 2. Light is more important than glass and pixels. 3. In the digital photography process, software is as important as gear.