I've been very pleased with the 100-500mm not only for airshows, but other sports as well. It's fast focusing ans sharp. Only beef has been the 300mm folcal length required to mount the 1.4x TC., with a resulting minimum 420mm too long for some situations. At times I've found my 100-400mm Mk II with the 1.4x Mk III has a better overall range and works very well with my R5.