Excerpt: There is a major manufacturing defect with this lense You can not focus this lens manually if you point it up at more than 45 degrees. I've tried several of these lenses and have had the same bad results. Canon WILL NOT take responsibility for it if you don't notice it within your warranty period. Double check you lense for this issue and return it!!! Canon does not consider it a manufacturing flaw , even though it obviosly is.
Conclusion: Excellent lens I have had this for about 8 months sharp pictures even captures birds in flight! Very light for the zoom range, well thought out lens. Easy to focus or adjust the zoom while framing a moving subject. I use it with a 1.4xII and its still tack sharp even on off hand shots.
Pros: Fast auto-focus, Superior build quality, Super-sharp images
Excerpt: This lens replaces my Canon 70-300 mm f/4-5.6 IS and is much sharper at longer focal lengths. In fact sharper with 200 mm cropped to equal image size of 300 mm than the old lens. Which is what I wanted. Functions extremely well with control setting on side easy to use. Seems like IS is better, too.
Pros: Does Not Extend, Fast / accurate auto-focus, Rugged, Sharp Images In Raw, Smooth Functioning, Strong Construction
Excerpt: I've read and watched a ton of reviews on this lens. And the review I read that made me purchase this lens said, "Just purchase the lens, you won't be mad." Well, I want to second that comment; just purchase the lens, you won't be mad!
Pros: Fast / accurate auto-focus, Nice Bokeh, Strong Construction