Here's an example of what I said earlier about the new 70-200. I was out on our local river and had just set up the D800 for a static subject at ISO 100 and aperture priority at f/5.6. I was ready to frame my subject and shoot when this guy flew by overhead. I zoomed out to 200mm, raised the camera, put the center focus spot on the bird, pushed AF-ON as I tracked him, and shot. I think the key was the incredible VR in this lens. Doubt I'd have caught the bird in perfect focus with no camera motion with anything else. The 70-200 f/2.8 probably would have focused fast enough, but I doubt the VR would have held up like this.