Quote Originally Posted by JTPAIN View Post
Surely the Canon 15-85mm gives better IQ and functionality than the Canon 17-55mm and the Tamron 17-50mm anyway?
In its focal range, yes, the 15-85 is more "functional." But the Canon 17-55's IQ is considered slightly better. And both the canon and Tamron have a constant f2.8 aperture, which is very, very nice and much more versatile than the 15-85's variable, and relatively slow, aperture.