I have a friend who has been trying out an X Pro-1 rental. He has mentioned quite a few quirks with it, not the least of which is lackluster RAW support from most tools. He has really only been able to use Fuji's software, which is far from great, to edit the RAW images (which are not quite "normal" in that the X Pro-1's sensor has a rather unique layout, and interpolation is not quite standard.)
He has also noted some funky issues using the OVF (optical viewfinder), which is not the same as a normal DSLR in that it has a parallax error. There are some odd problems around how the AF points when using the OVF don't really match up well with the actual contrast AF points of the sensor. He has mentioned on a few occasions how the EVF is not particularly great, and he has opted for the OVF more often...despite its parallax and AF issues.
He loves the IQ (its apparently excellent), but there is definitely a learning curve associated with the X-Pro 1, as well as some funky quirks and issues that seem to take some time to get used to or work around.