This lens is great. I have three of them, two Nikons and one Canon. The Canon version has a non-USM motor so it is loud and somewhat slow, but I love my Nikon versions. I haven't looked to see if there is a new USM version for Canon. If there is, I would like it much better than the version I have right now.
Of course, the lens gets a lot slower (f/4.0) at close focusing distances, but beyond about 10 feet it stays at f/2.0.
5DIII, 5DII, 7D x5, 6D, T2i, T3, 1D X, 10-22mm, 16-35mm II, 18-55mm II, 18-135mm IS x2, 70-200mm f/2.8L II, 24mm f/1.4L II, 50mm f/1.4, 50mm 1/1.8 II x2, 85mm f/1.8 x2, 100mm f/2 x2, 135mm f/2L x2, 200mm f/2.8L II x2, 1.4X III, 2.0X II, 60mm f/2.8 Macro, etc. only had room to list a few Canon items