I have the 28-70mm f3.5-5.6 but I've only used it a few times. Once I used it thinking it was the 85mm f1.8 and only spotted something was up when I couldn't select f1.8.
I think I could use a 17-28mm more. I think I could go out with that and a 35 or 50mm.
I've just read a review which mentioned colour cast in the corners, distortion and non linear focusing. Of those any colour cast would worry me the most but I can't see anything too bad in the samples...
The Tamron 17-28mm 2.8 Di III RXD is the lightest ultra wide angle zoom for Sony E-mount, but is it as good as the 28-75mm standardzoom?
phillipreeve.net
Have you seen any colour cast in the corners and other that that what do you think of the lens?