Excerpt: I have bought about 15 Canon lenses and this is the best. It costs the most but is worth it. The lens is very sharp and not too heavy. The 2.8 f stop along with the stabilizer makes it very useful in everyday usage. I am very pleased with the purchase.
Conclusion: I've owned this lens for over 6 years. In that time, I've realistically taken over 100,000 images with this very lens - and that's a conservative assumption looking at shutter counts. This is it for me. If I never purchased this lens, I would have probably abandoned the APS-C format all together because, honestly, there is no other lens I can think of that provides the useful focal range, fast aperture, and terrific image quality.
Excerpt: The only thing I would say is that for the price this should have had a little bit of a better construction. A week or so into the use of the lens the zoom is starting to feel less smooth then it did out of the box. Overall it is a beautiful piece of Canon glass.Bottom Line: Do it.