One other thing - to address Sinh's comment about IS not stopping action, only camera shake. While that is certainly true, IS does help with action shots in the sense that while it doesn't stop the action happening inside our field of vision, it does help us stop ourselves when we get to the right subject framing before/as we depress the shutter. Unless your subject is coming straight towards you, chances are with your 'action' shots you are moving/tracking the subject. So in the sense that it helps dampen/suppress motion up to the point of shutter actuation, it in effect does help with action shots.