Well I did some tests today with the 11-20mm, first thing I checked was decentering and it was dead on (side to side/ bottom to top).
Second was how bad the flare is, which isn't huge to me, it does flare but the good part is I had to really try, with my 7D mkII I could see it through the viewfinder and I can adjust (hood helped). It would be nice if it had better flare control but it was no big deal to me.
Sharpness is very good but not prime sharp or equal to my 24-70 mkII, but I didn't expected it to be, so far I'm very happy with what I'm seeing, need to use it more the next couple weeks.
I have to say I got this lens mainly for astrophotography on my 7D mkII, if it was not for that I would have just gotten an Canon 10-22mm.















