This lens, even with the EF-S format and inferior build quality, produces surprisingly good images, outcompeting even such "L" lens as 24-105/4 L IS USM. Particularly related to chromatic aberrations which in this lens are neglegible.
May 28, 2013
Very good and quite bad...
I've hade this lens on my second body (7D) for nearly one year and I still think that's the best APS-C standard zoom on the market, as far as optical performances and focal range are concerned. Distortion at shortest focals is an issue and corner sharpness wide open is not impressive at all, but that's to be expected considering the kind of lens. What you wouldn't expect from such a lens, considering its price, is the poor built quality. It's not terrible, it's just not in line with the price. Same thing for the expensive hood, sold apart. I really hope for a "Version II" with a better built quality.
May 20, 2013
Badass but dusty
This lens is really great, it's super fast and quiet even in low lighting. Portrait are beautiful less noise then my old lens. I fell in love with this lens after upgrading it from my EF-S 18-200mm f/3.5-5.6 IS. It doesn't have the zoom range as the EF-S 18-200mm and a lock, but it's lighter. The build quality is bit similar. The EF-s15-55 get really dusty inside easily and fast though which I don't like. I would love to see an update of this lens.
L build quality.
EF 24-70mm f/2.8L II USM & EF24-70mm f/4L IS USM Features.
April 8, 2013
I read all the negative on this lens but after carefully weighing my options, I purchased it and I have to say, I'm happy I did.
Let me say first that it should be obvious that any zoom lens will have dust issues as they get older. Pumping the focal length in and out will carry dust into the lens body. It's cant be helped. If there was some unfortunate folks that got a lens that didn't live up to the Canon name, well that's why we buy from reputable sources, warranties.
All and all I'm ultra pleased with this lens, wishing there were more constant aperture, internal focus , fast lenses in the line up.
April 6, 2013