I am soooooooooooooo impressed with the D4 today was the real test for it out in the field. I hiked way up high on a mountain side to get these(4 0f 485) shots. Out of 485 and I was shooting at 10FPS only 4 were out of focus and that was due to me slipping on the mountain side. The D4 is built tough as a tank, I was concerned at first because it is noticeably lighter than what the D3s was however it's just as tough if not more so.