I waited until I really put the camera through its paces before writing this review. I just finished photographing the $40,000 Grand Pix and the championship round of rodeo action at the historic National Western Stock Show in Denver, where the lighting conditions for action photography are not ideal, to say the least.
I am thoroughly impressed with the low-light, high ISO performance and capabilities of this camera. I was able to shoot at 1600-2000 ISO (using 70-200mm f2.8 IS) with ZERO qualms about image performance (and my ability to tweak the images using Photoshop Elements) and send them along to magazines and websites for use along with my articles and columns.
The 10 FPS is awesome for being able to capture peak action, and the white balance AI is impressive. I need to move from one arena to another in order to capture events at the stock show, and the AI nailed the white balance no matter what type of overhead lighting was in use. I had to color correct my images all the time when I used the 20D, not so with this puppy! Some of my photographer buddies using Nikons were pleasantly envious of the 10 fps burst performance (the guys using other Canons just drooled!). They were getting 1-2 shots of peak action for my three shots. That extra 1-2 shots creates a better chance for hitting the perfect action moment.
On the real-world experience side of things, I can say out of about 700 images shot during the rodeo championship round, I had to delete less than 70 due to AI Servo focus mishits (for a 90+% keeper ratio in difficult lighting conditions with action photography). With my 20D, I usually had to delete about 40% of the images. Needless to say, I am quite pleased.
The only downside I have noticed so far is that the AI Servo mode seems to lose a bit of quickness in nailing the focus in low-light conditions when the battery is at less than 50%. I haven't noticed anything other than that, however.
I highly recommend this camera for sports shooters. You won't be disappointed.