There must be over 10k posts about this subject in this very forum. Just spend some time reading.
There were some problems with early units. I got a VERY early unit and have not had a moment's trouble.
>I see a lot of adverts for refurbished D600's running into >the hundreds of units being offered. > >This is not reassuring as I want to buy a full frame camera >and don't want to buy trouble. > >Are these returns "normal" or is there a problem >with the D600? > >Regards, > >Norman Silva.