Dave, all I have to go on are the ISO crops, and limited experience. While the center is sharp, the mid frame and corners are blurry.

We sold our 24-105mm f/4L as it couldn't consistently put out a sharp image on a crop body, and it's long end ISO crop images look to be a similar softness to the 70-200mm f/4L USM. If the ISO charts are soft on a 10MP 40D, so they'd seem even softer on an 18MP 7D (yes, I know, not for an equivalent sized print). I know from the 24-105mm that this softness is obvious in high contrast black and white in bright light situations, such as the ISO chart. As we have a black and white dog, and she'll be running in bright sunlight, I'm expecting this same softness to be a real world concern, just as it was with the 24-105mm.

As a real-world sanity check though, I will search the flickr pool and see what I can find.