14mm lens test up on photozone

Vignetting is the easiest problem to solve in post processing. My experience is that if you are working in very exact situations, like architecture or interiors, you'll be mostly using a tripod and low ISO, so pushing a bit the corners won't be a stress to image quality. If you shoot high ISO situation (street, events, night scenes) vignetting may not be a problem, and sometimes it can be used as an aesthetic factor.

Pity Photozone.de does not test eventual flare problems, which may be significant in a lens of this angle. Even the examples published say nothing about this.

The linear distortion performance is stunning. Remember that a near competitor, Olympus 12mm for m43, has 5+% distortion before software correction, and all Fujinon 18mm users have learnt the price you pay for distortion correction in optical qualities. And even the 18 and 21mm Zeiss for full format, that are well considered, have a 1,8% distortion that needs to be corrected for architecture work. Only a few RF lenses show a similar performance, but to use them one has the choice between shooting film or selling car and something else to buy the Leica M.

All in all, I would say that the 14mm is a good reason in itself to enter the Fuji-X world (I thought the same of the 35mm). Hope my bank manager will understand, when I will try to explain him the matter.