Not the easiest lens to use at airshows - it's a heavy bugger and the AF isn't really fast enough for head on tracking (on a D700). If you lose the 'plane as it's coming towards you, it can struggle to pick it up again before it goes over your head. IMO, the Nikon 70-300 does a better job. Not used it for motorsport yet - it'll still be a heavy bugger but it may cope better with the lower speeds involved.