I have the canon 70-200 2.8 but hardly use it unless I am shooting at a horse show or something else outdoors, I use the canon 24-70 for models.
the 70-200 is a great lense and can reach out to get some good photos
here is one of an air ambulance, it was shot in automatic because the helo was hauling ass and I only had a few seconds to get the shot
http://www.landofvenus.com/accident/accident6.jpg
and one from a horse show of my horse
http://www.avalanchefriesians.com/he...g/IMG_8440.JPG
the helo was the farthest away but the horse was a ways also, on the far side of the arena