I've owned the 80-400 mm F:4.5-5.6 VR Nikkor telephoto zoom lens for well over a year. And all I can say about it is that it is a fantastic product. As anyone who takes wildlife photos knows, it's wonderful to be able to shoot handheld. Also, with a rapidly moving subject far away from the camera, it's great to be able to find the subject and zoom in on it, and then follow it. This is especially true of birds in flight. It's also nice to be able to shoot wider images without having to change lenses in a dusty or rainy environment.
This lens does all that without difficulty. It is exceedingly sharp, with brilliant color and good contrast resolution. It's fast enough and long enough so that with the D800 it gives sharp, low-noise images of distant subjects, while allowing a shutter speed that avoids motion blur. Although it is a wonderful wildlife telphoto, it can also be used a a distance of a few feet as almost a macro lens. And at the wide end, it's sharp and decent for architecture and some landscape work too. This lens is very lightweight for the quality of the build and the optics. Although there are plastic elements, I am able to take it everywhere, and there has never been a problem with dusty, wet, hot, or cold environments. I often go to wildlife refuges where there are other photographers using longer prime lenses. The images I get from this lens and the D800 are at least as good as those obtained with much more expensive (and much heavier) gear. Without a doubt, this is a pricey lens, but it's well worth the cost, and has optical quality and reach you could easily pay twice as much for. You won't regret owning one!