I agree that the XF18's IQ is really quite impressive- plus fast AF and small size. I was shooting Canon with 16-35L II and the Zeiss ZF 28 f2 and I think the XF18 "can fight". Too bad it's been eclipsed by the XF35 and 60.
Still got hope for the 14mm. If not, there is still the Zeiss 12mm...