I have the Nikon 80-400 VR and Nikon 80-200 AF-D. I love both for bvey high IQ. I also have the 18-200 VR for casual shooting. I wanted a goos quality lightweight telephoto zoom. The Sigma 50-150 or the Nikon 70-300 VR coms to mind. I know one is fast and the other has VR and there is obvious FL difference. I also like to shoot wide open most of the time. Which would you recommend? Why?