So I've had my D600 for about 2 months now. Dealt with a great outfit who gave me the option of a $500 refund or $500 store credit once the $2k package came out in early Dec. Anyway, I'm using the kit 24-85, 85/1.4G, 70-200/2.8 VRII and 50/1.8G with it. I would say that about half my shots have a soft center using the center AF sensor. Not terrible, but enough to cause some frustration. It is about the same degree(not scientifically analyzed) with each lens leading me to believe that it is the body. So I will likely be taking it to a service center in Cherry Hill, NJ. Just wondering if this has been experienced by any other members. Also, I cleaned the sensor for the first time today after about 2000 clicks and it is absolutely spotless. I have been fearful of even checking, but I now feel at ease.