I currently own the 18-200 VR but was thinking about going back to a 2 lens setup using the Sigma EX 18-50 2.8 and the Nikon 70-300 VR. My question is does the 70-300 has better optics than the 18-200? If anyone has had both or has used both I would appreciate their comments. That is the main reason I am switching back to a 2 lens setup is the image quality. I love the versatility and how well the VR works on the 18-200 but the image quality if not that good.