I wonder what really differences there are for practical photography between "similar" Nikkor zoom lenses? I'm a amateur nature photographer. I own two zooms that I normally carry in my backpack when doing landscape photography, i.e. an AF-S Nikkor 18-70/3,5-4,5G ED (that followed my D70 kit), and an AF Nikkor 80-200/2,8 D ED. Would I recognize any practical improvement if I invest into the AF-S 17-55/2,8G and the AF-S 70-200/2,8 G (I know that I would have the VR)? Today my camera body is a D200. D. PS: you might know some Web-links where these questions are discussed.