I've been wanting a fast telephoto zoom for a while, and Nikon's has been out of my price range. Sigma has a new(ish) 70-200 that's significantly cheaper, but seems to include mostly the same features — optical, zoom, etc. The Sigma is missing the vibration reduction, which probably accounts for most of the price difference. Does anyone have any experience that would allow them to compare the two? I don't buy new lenses often, so if there is a sizable difference in quality or longevity in the Nikon, I would rather wait and get that. If I were to go with the Sigma how much would I miss VR? I've never owned any non-Nikon glass for my D70s. Thanks.