During several years I had been looking for a lens going beyond 300mm for my F70/F100 equipment: the idea was to get a lens that could be used in all the telephoto lens, without having to change continuously and preferably improving the optical quality of my Nikkor 75-300/Tamron 200-400.
A friend of mine let me make several shots with the Tokina and it wasn't bad, but worst than the 75-300. I wasn't convinced in buying the Nikon 80-400 due to to lack of AF-S, but all the tests said that it performed very well optically, also AirNikon and several users gave me very good references about it.
I bought the Nikkor 80-400VR last week and yesterday I had the first rolls developed. Believe me, it's worth the price: quality was very good at all focal lenghts and apertures, I even did several action shots at 400mm and they were extremely sharp
. Focusing was faster than with my older lenses
If you are going to wait perhaps it would be better to save a bit of money in the meantime and go for it.
Good luck with your choice
There is a very fine line between 'hobby' and 'mental illness'.