I have the 80-400 and used it extensively on my D100. It's a great lens, but wish it was a little faster and had AF-S. It "hunts" quite a bit in low light. If Nikon ever does create one with AF-S, I might ditch the 70-200.
I had one but sold it to a friend. The lens performed quite well but I sold it to help fund a 70-200mm f/2.8 VR because I felt that having all f/2.8 glass was better for shooting sports action. I used my 24-120mm VR as a walk-around and the 80-400mm VR zoom for distance shooting and they were both great lenses. The 24-120mm VR is back in it's original packaging, stashed away waiting for it's new owner to say that she is ready for it.
If the 80-400mm VR sounds like something that you wish to add to your camera bag and you can afford Nikkor glass...the lens will serve you well.
I had a 80-400mm VR and I sold it to finance a 200-400mm. The 200-400mm is an outstanding lens but I regret having sold the 80-400mm. It did the job for me. It was a great lens to use in the locales that I haunted.
It's a great lens even at 400mm. The only problem I have with mine is that it's not really fast enough focusing for birds in flight and the like. If you would like to see some examples of pics I have taken look at my posts in the birds and animals pictures section of this forum.
The great thing about it is that it is hand holdable - the VR really works. The tripod mounting bit can be detached which saves a bit of weight and makes the lens camera assembly easier to hold.