There is an advantage of using FX lenses on DX camera bodies, and it is that you are using the sweet spot of the lens (the center portion). If you use a DX lens on a DX camera, you may (on some lenses) get some viginetting (dark corners), but a FX lens on a DX body is using the center portion of the image.
Another advantage is the crop factor (of 1.5 for Nikon).
So a 200mm lens is actuall 300mm.
The down side of a DX body is that you would not be able to go as wide for wideangle lenses (because of the crop factor) as FX bodies.