I have that issue as well. Ports with Cvs near really stutter! The large air fields with the ack firing are almost as bad. Of coarse I do get frame rate drops in those situations, not extreme but from steady 59/60 to 55 and blip down to 46. By blip I mean really quick. I am still getting the freeze frame effect, just about every where. Mostly on DX11 as I still play with both versions. I do notice it in DX9 but nowhere near as offten as in DX11