Photoheadonline makes a head-to-head comparison with two ZM lenses and two Fujinon in the focal length 18mm and 35mm. The result favours Fujinon over ZM for mostly two reasons - the quality-cost ratio and the extra speed of the Fujinon. It also debunks the folklore of the Fujinon 18mm being mediocre. If you are shooting on an X-Pro 1, it is naturally more reasonable to choose the Fujinon lenses over ZM, however let's not forget that the ZM lenses are full frame 35mm lenses. They are designed differently and project images on a format that captures more information than APS-C.
Enjoy the review at http://photoheadonline.com/2012/06/03/zeiss-18mm-f4-vs-fujinon-18mm-f2/ and http://photoheadonline.com/2012/06/04/zeiss-35mm-f2-vs-fujinon-35mm-f1-4/