Helena, very nice pic's with the Heliar.
I can confirm your first impressions on that lens, new for me as well, my first post with it being the first pic on this page..
There is oc. vignetting but not really bad, super WA's must, for my taste, have some vignetting. The LR profile for the Heliar works very good, but overcompensates for vignetting. Distortion is quite good, to be corrected for strong architecture. Sharpness in the corners very good.
As a owner of the 16-35 FE you don't really need the Heliar. I bought it because of it's size and it works with my Leicas as well very good.
Cheers
Werner