leicashot, I think this picture is a good illustration for the adequacy of having f2.8 as fastest aperture with a wideangle lens.
In some threads about fast wideangles/C-Biogon one reasoning was often that f2.8 would not leave you with the choice to throw backgrounds ("sufficiently") out of focus. Obviously it is true that f2, f1.4, let alone f1.2 give you more options, especially when the focus distance is not in the nearer range. But I find f2.8 plenty selective. Even with the f3.5 28mm Skopar (alas, now sold to a fellow RFFer) there was a lot of background blur to go around when the focus distance was reasonably close.
Greetings, Ljós