I have tested this lens on a Nikon F100, a D100 and a D200. To start with the conclusion: it's a mixed blessing. The build quality is very good. It's built with a mix of some plastic and lots of metal, and it has the look and feel of a quality lens. The markings are not engraved on the lens, as is usually the case with professional lenses. Instead, the markings are printed on the lens, which makes them more susceptible to wear when the lens is heavily used. I could find no play in the focussing ring, although it moves nice and smooth. The zoom ring is pretty stiff to turn, it probably has to be to prevent creeping when holding the lens with the front element pointing down. The zoom ring is in front of the focussing ring. That's the other way around compared to the other Nikon lenses I have! If you have this lens on the camera all the time, you'll probably get used to the layout soon enough. But if you switch lenses all the time like I do, I'm not so sure about that! Focussing does not turn the front of the lens, but it does change the length. Zooming in changes the length of the lens a lot. At its shortest length the lens measures 171mm, at its longest it is 243mm, a difference of 72mm. Usually there is a little bit of play in the front lens element that extends, but I could find no play at all. Good! It's a pity that Nikon didn't incorporate internal zooming in the design. That would have dealt with the change in length while zooming and the lens would also be less vulnerable to dust and moisture. On the other hand it would probably make it a lot more expensive to manufacture as well! Auto focussing is hopelessly out of date! It's like the old F801 again with the first autofocus lens available. On the F100 it performs reasonably well, but on the D100 it is very sloooow! Lately, I've been using the lens on a D200, which has a better and faster focussing technique, but to be honest... there's not much improvement. In low light conditions it hunts a lot as well. Not good! These characteristics simply make this lens totally unusable for any kind of action photography. This lens definitely needs AFS! I usually have it on manual focus now, it takes a bit longer but at least you get decent shots. A good trick is to prefocus the lens, wait for the subject to enter the in focus area and then press the shutter release. There's a ring on the lens just before the focussing ring that lets you set the lens on auto or manual focus, an extra button will lock it there as well, works like a charm! There's also a switch to limit focussing from infinity to 5 metres or from 4 meters to 2.3 meters depending on where the focus is set when you activate the limit. Vibration Reduction (VR) has 3 settings: Off, On and Continously On. When set to On, VR mode starts immediately before the shutter opens and affects only the projected image. When set to Continously On, VR mode starts when the shutter release is lightly pressed and the viewfinder image is continously adjusted. According to Nikon, VR has to be switched off when the camera is mounted on a tripod! The tripod collar is removable. It does the job, but no more than that. Nikon could have made it a bit sturdier, but hey, who's complaining? This lens is made for handheld shots!

Sharpness
This lens is a little soft wide open at f/4.5 and f/5.6. But stopped down to f/8 it is great and at f/11 or f/16 it gives excellent edge to edge sharpness.

Color and contrast
Vivid colors, very good contrast. There is hardly any trace of colour fringing. The image quality is very impressive.

Flare and ghosting
Virtually non-existent, very good! I usually leave the hood at home!

Light falloff
Just a tiny little bit of falloff but only at wide open aperture. With the lens mounted on a D1/D2 series digital camera this is less of an issue because of the smaller angle of view.

Geometric distortion
The usual slight barrel distortion at 80mm, some pincushion at 400mm and neutral in between. I really had to look very hard to find any distortion though, so don't worry about it.

Vibration Reduction (VR)
VR is a great feature and it works very well on this lens. I was able to take sharp photographs without a tripod in low light conditions at 1/25 sec. (and slower!!), which I could not have taken without VR. The number of "keepers" will definitely increase! Just look at the shot of the Red Deer above, the sun was long gone and the deer was walking under a couple of tree branches. There wasn't much light left to work with!! I took this shot at 1/20th of a second, handheld!

Every time I work with this lens, the same thought crosses my mind. If only Nikon had added AFS to this lens. That's all it needs to make it an absolute winner!! I would gladly have paid a few hundred Euro extra for AFS! The build quality and optical performance are very good. The Vibration Reduction system is simply astonishing. In the old days, before VR, would you have dreamed of hand holding a 400mm lens? I don't think so! So even though this lens is a mixed blessing, I'm still glad I bought it!