Hi guys, In a few weeks time, I'll be getting some extra cash. I'm thinking of upgrading from my Nikon D100 to a D200 or a D300. The last one would be the best alternative. However, I really like my camera and am thinking about keeping it as a backup. Might this be a good idea? Does anyone know if there are many differences between these cameras? Or can I buy a new camera, have a quick read thrugh the instructions and be good to go from my experiance with the D100? The last question is the one that conserns me the most at the time... I'd greatly apprechiate any and all help.