apparently there are some folks out there with questionable 70-200G f4 copies. I was blessed with an exceptional one just like you. Sharp wide open across the board and a gem for fast focusing as well. Love that sucker for sure. I was one that apparently discovered with that lens, which I shared with Sony's tech department, that when you are achieving a shutter speed due to good light, 1000th sec or better, it is advisable to shut OFF the Steadyshot or just switch off the OS on the lens OFF as it tends to work against it at times. The consistency of superbly sharp images above 1000th sec without OS on is like 100%. If you don't believe me try it. I tested it so much it was crazy and this is what I discovered. The Sony tech department was a bit surprised, but got back to me saying they also confirmed this to be true. They expect a firmware update on the lens at some point as well as the A7RII, that will eliminate the error message stating the lens isn't supported at times when in fact it IS (just ignore the message as they said). The lens, when you get a good one, is flat out superb.