It is a bit heavier than the 70-300 so will need a bit more focus on strength and long lens technique to keep it stable. The OS is pretty good but for panning or shutter speeds over 1/500 I turned it off anyway.
As I mentioned earlier I tended to not use the full 400mm all that much, though how much benefit I really saw I can't say. I just had it in my head at the time that it wasn't at its best out there
















