AF-D 80-400mm f/4.5-5.6 ED VR

Coming from the excellent and affordable Nikon 70-300VR, this lens seemed like the natural upgrade to do.
Well, after using it for a few months now I'm a bit underwhelmed, and it doesn't feel like much of an upgrade anymore.

The optics and overall build quality are quite good. The lens feels solid, the hood is excellent, the controls work great, VR does a good job.
IQ-wise it's on the par with 70-300VR up to about 200mm. Over that setting it's visibly better, but at 400mm it does soften a bit. Stopping down helps, but it doesn't match the lower focal lengths.
So far so good.
In AF department this lens is more of a downgrade for me, and before getting the D300 (I had D80), acquisition was slow and prone to hunting in less than perfect light.
D300 solved half of the problem - it doesn't hunt nearly as much, but it's still on the slow side. The focus limiter is a real help and improves things further (IMO - every telephoto lens should have one!).
The tripod collar flexes, significantly decreasing sharpness. Replacements don't go cheap either.

Hopefully Nikon will come up with an improved design that would unleash the full potential of this lens

No matter how big your lens, you will no doubt always covet something better. What is affordable to some certainly isn't to others, but this piece of kit has given me some very good pictures and hours of pleasure. I rarely use the lens at anything less than full zoom so I would be happy with a prime lens if I could afford one. Unfortuneately , you can't use a converter with this lens either, but having said that you would need very good light to make use of it. The VR works very well, and as I take the majority of my pictures whilst hand held it has proven it's worth.
I have some pictures in the gallery if anyone wants some comparisons, but I would buy the lens again given that choice. I was considering the Canon equivalent but decided the Nikon D200 was a better camera than Canon had on offer for a reasonable budget.I haven't tried the Canon but would like to do so for a like for like trial.

Another great lens from Nikon but now getting a bit dated. With a Silent Wave Motor (SWM) it could be much faster but even so I find it perfect for use from a hide with a monopod or when just walking. The Vibration Control (VR) works very well and the sharpness of the images is superb. Still learning but great so far. Will post samples shortly.