I'm done with September. Quite happy with the month. I did manage to shoot every day, but had to go with easy safeties on some days. Didn't get the typical end of the month blues, but instead had a good run towards the end and felt my work improving. 28mm was too wide and yet not wide enough for me. I struggled with the FOV it offered. Somehow I find myself a lot more comfortable with 35mm.
The lens... Usable from wide open, but in typical way gets sharper when stopped down. For landscapes f5.6 is enough to provide corner sharpness, but there is some vignetting on FF even at f8. When set to infinity everything is sharp from around 3m at f8, so pretty easy to snap casual shots. Didn't push for starbursts as this lens is not as good on those as M28/2.8. Sharpness is good enough, but nothing to get stoked about.
Now that I'm done with this lens on SIC, I think I could put it on sale. I find both M35 lenses better for me. I think they perform better and, as I said, I like focal length more. If I keep 28mm on the shelf, it will be M28/2.8 due to better starbursts and PF performance, but even that would get in my camera bag only in rare occasions.
Wide open:
f4:
f5.6:
f8: