Quote Originally Posted by neuroanatomist View Post
I think the 17-55mm is a better option. The 17-55mm is actually a little sharper than the 16-35L II when comparing both on the same APS-C camera. The 17-55mm has a more useful focal range, and has image stabilization. The 16-35L II is significantly more expensive. It's true that the 16-35 II is weather sealed, but that is only useful is you're using it on a weather sealed body (the T4i is not, the 60D has some sealing, but really you'd want a 7D for decent sealing); also, a filter is needed to complete the sealing and 82mm filters aren't cheap.

If you were asking about an ultrawide zoom for a FF camera, the 16-35L II would be the recommendation. For a general purpose lens on APS-C, the 17-55mm is the better choice of the two.
What is your opinion the Canon EF 24-70mm f/2.8L USM vs the 17-55mm worn on a 60d? Would you still go with the 17-55mm for an all purpose lens?