Need help deciding on D600 or refurbished D800 body considering the following: Current lenses (all old AI, not auto-focus) 28 2.8, 55 3.5 micro, 85 2.0, 180 2.8, 35 PC. I will also buy an AF zoom for "casual shooting" such as a 24-70 2.8. Is a new D600 now less likely to have the dust/spot problem than earlier ones, or would a refurbished D800 (close to same price as new D600, but less warranty) be safer? I'm not afraid to clean the sensor but would prefer to not do it frequently and I know I am too picky to ignore any spots. And, per above, I'll be changing lenses often. Can either camera accommodate an old 21mm that requires shooting in mirror lock-up mode? I know that finding a place for the accessory finder will be tough. Or do I trade in the old F bodies and lens for a new super wide? Will my PB-4 bellows work with either the D600 or D800 bodies?