I’m so sorry it took so long to reply to this post.
In my opinion the Canon 70-200 f/2.8 II L IS USM is one of the best pieces of glass available right now in Canon's EF line-up. It's certainly one of the finest that I’ve gotten a chance to play with!
It's extremely sharp throughout its focal range; and has great color, contrast, and IQ.
An easy 9.5 out of 10!
The only real drawbacks: The weight. It’s a hefty piece of glass, and if you're not use to lugging around a small cannon, then it may take some adjustment. That also means that the auto focus may take a tab longer to run through the entire range. Not a deal-breaker in the least! The second issue is, on a crop sensor camera, that 70-200 mm quickly turns into something closer to a 112-320 mm lens, which may be a little “too telephoto” for some applications.
But, on a full frame camera, like a 5D, the lens is an amazing one-stop shop. It’s awesomely fast for its range, has great sharpness, and an overall amazing image quality.