Mike
I bought this lens after trying out the 70-200mm Tameron GII. As someone who primarily does landscape and wildlife photography, I needed something that could fill the frame at longer distances. After quite a bit of research, I landed on this lens. Several months later and Im convinced I made the right choice. Its been very quick to lock onto subjects and reasonably sharp. (The attached image was taken on a Nikon D500 @ 320mm 1/800 sec f/6.3 ISO6400) My only issue with this lens is how it receives filters. The front element is surrounded by a rubber gasket of sorts which makes using a 67mm (the lens filter size) sized filter extremely difficult to remove. This issue is further exasperated by using circular ND and Polarizers. The first time affixing a 67mm circular polarizer to the lens took approximately 30 minutes and some careful work with needle nose pliers to remove it. I ended up purchases a 77-67mm step-down ring to comfortably use filters without the fear of them becoming perminately affixed. In future variations of the lens, I would hope that this rubber piece is removed or reworked.