Summary: I must have gotten a bad lens based on these reviews but then again maybe they don't have to look at thousands of images at 100% in a photo editor. This is the worst lens I've ever owned. It is soft, soft, soft. Even my cheap 50mm 1.8 is significantly sharper.
Summary: Canon generally makes excellent lenses, but my copy of this lens is awful! Even at f/8 with a fast shutter speed and low ISO, images are blurry when blown up to 100%. It also suffers from severe CA, particularly in bright settings.