|Test Photos of Darby while I got acclimated to my new Canon lens|
If I'm being completely honest my first impression of my new Canon EF 70-300 f/4-5.6 IS USM lens was: "Geez! That's a noisy autofocus! I wonder if something's wrong." After some quick research, I determined nothing was wrong; it's just the nature of this lens.
Other than that, I have been really pleased. It's a better performer than the Tamron 70-300mm Di LD lens that it replaced, but at 3x the price it ought to be. And the addition of Image Stabilization is likely to increase my number of handheld keepers many times over. That's assuming I can get the hand of photographing fast-moving subjects, like the one above.