First off, NAS made me do it. I had to get the latest Nikon. Then I was going to take the D600 back and trade up to a D800e, but my wife stopped me from spending more money. The smaller, lighter D600 fits her small hands much better than mine. So we kept it for her use. I personally believe my D800 is more than worth the extra money.
If I could afford "all three cameras", I would also get a D4.