I'm completely lost now with this announcement.
I love wide angle, and used tokina 11-16 on crop.
And i love zeiss. They now have 3 ultra-wides: 21, 18, 15.
Now i'm moving to full frame, and was considering tokina's replace (i miss it so much).
21mm seems to be an outstanding lens, but not as wide as i would like.
18mm is a sweet spot focal length to me, but appears to have unpleasant color errors in rendition.
And a new 15mm is lovely but costs.. and it may be bit too wide for me.
Maybe it is time to go 100mm macro instead and explore