This lens is great compared to Nikon 70-200 VR2 grip. 4- Built like a tank. I dropped it twice on hard ground from 1.6 meters, nothing but scratches 5 - very weak (no more than Nikon) and very good ventilation (almost the same as Nikon) 6 - very fast focusing with no disadvantages in weak Light (with Nikon D600 and D750) recommended high,