I recently traveled with to the north of Sabah, Kudat. I had the opportunity to test the 300mm 2.8 Nikon lens on various subject. AF speed was quite fast but when TC 2x was mounted, AF can missed and sometime does not focus. VR was excellent, it help a lot when using the TC 2x when you move a lot. I only manage to test it on a monopod and not on a tripod. Image quality and sharpness is excellent on 300mm, adding TC 2x does reduce sharpness of the image. Will be adding this to my gear list(future purchase).