Nikon AF 80-400mm VR f/4.5-5.6D?

How good is the Nikon AF 80-400mm VR f/4.5-5.6D lens for concert photography? Would you say it's a good alternative to the common 70-200mm f2.8, especially when having to shoot from afar?

If you need that much zoom, you probably are not an authorized photographer. If you are not an authorized photographer, you will never be allowed to take that lens into a concert.

If you zoom at all, you will quickly approach f/5.6. At that aperture, you will need to astronomical ISOs, like 5000-6400 or more. For the money that lens costs, you would make out better buying a new body with a high pixel count with excellent low light performance. Then you could use the 70-200 at f/2.8-4.0 and ISO 1600-2000 and get a usable image. If you get a D600 ($2, 000), you can crop like crazy and get a 12MP image that would look almost as close as if you were using that 400mm lens. The D3200 would allow a lot of cropping (effectively "digital zoom") in addition to the 1.5X crop factor, so it would look like you were using about a 500mm lens instead of 200mm. You can do your own research (DXoMark, dpreview) to evaluate the low light performance of the D3200.

The D7000 has excellent low light/high ISO performance and the body costs half as much as the 80-400 lens. It's "only" 16MP, but you will still be able to crop somewhat, probably achieving a "final effective equivalent" of 400mm.

Does my logic make sense?