Bought mine September 2012, the day the shop got its first shipment (pre-ordered). Have made many thousands of images, and am quite delighted with this body.
I am really not wanting to trade, but hope the gurus will have some useful advice.
On another post from an Italian user who can't get his D600 to shoot, I noted that I also have had the diopter refuse to adjust (twice). Perhaps this was related to battery charge state. This adds to my nervousness.