Has anyone else looked at the lens reviews posted at SLRgear.com? I don't know how accurate their tests are, but they do present them in a very convenient form. If you click on their 3-D blur chart, it provides two sliders for aperture and zoom (for zoom lenses) that lets you see how the lens performs on the sharpness test throughout its range. There are also nice plots for CA, vignetting, and distortion. It provides an interesting way to compare lenses, as you can look open the 3-D blur charts on more than one lens simultaneously.