So far so good. There is vignetting at 2.8 but that is to be expected. It also is a tad soft on the edges at 2.8 but is pretty damn sharp in the center. Stopping down to 4.0 makes a significant difference and above that there is no vignetting.
I've always regarded the 16-45 as an incredible lens for the money. I shot the 16-50* back to back with the 16-45 and the 16-45 is still the value leader. But I have to say that at 16mm with both at f4.0 the 16-50* was sharper than the 16-45.
Now I'm thinking K20d w/16-50* and 50-135* as the "do everything" setup and get a K7 with 15/31/35/43/77 as the "street/prime" setup.
Now I just need another $2K
