Excerpt: Used this lens at a Canon live learning seminar and it was great, so ordered one from Adorama and they delivered promptly and in great condition. The sharpness of this lens while hand holding it is fantastic. I had a 170-500mm of another brand, but never could get perfectly sharp photos. Very pleased with this lens.
Excerpt: Very nice lens, great images. It's disappointing that it's not weather sealed. It's also disappointing that it won't autofocus on any but 1D-level bodies when using the 1.4x (or 2x) teleconverter. Zoom creep is customer controlled; you can tighten it up if you want, but that makes zooming tighter and harder too. The image stabilization works well but leads to a false sense of security. I got many blurry images when not paying attention to shutter speed.
Pros: Consistent Output, Rugged, Strong Construction
Cons: Blurry Focus, Lens Creep, Not Weather Sealed
Excerpt: I shoot youth Football and Baseball and this lens lives on my camera about 6 months of the year. It's big and heavy but the breadth of range allows for flexibility that I'd otherwise need two bodies for. I actually like the push-pull zoom because it seems faster but it is a disadvantage when shooting through the fence on baseball.
Excerpt: This was a present from my wife, upgrading me from a 70-300mm EF. The extra 100mm really makes a difference for those more distant subjects, and the optical quality is world's better. I love the push/pull zoom, which leaves the lens well-balanced in my hand, and the IS makes a huge difference in my pan shots. Would not hesitate to recommend this to anyone.
Pros: Consistent Output, Fast / accurate auto-focus, PushPull Zoom, Rugged, Strong Construction
Excerpt: I use this mainly for wildlife and outdoor sports. It is a pretty good lens. Not as sharp as I might like. I have gotten some pretty good shots out of it though. I do have to admit that I tend to shoot hand held quite a bit and the IS handles it pretty well, even at 400mm. I kind of like the push-pull action and find that I am able to adjust pretty quickly with it.
Pros: Consistent Output, Durable, Strong Construction