Iridient Developer 2.3.3
and LightZone 4.1.0 beta 6 (free)
My 'quick'n'dirty' comparison.
* The camera and lens are considered as pre-production units
I still prefer ID, but I was really impressed with LightZone and LZ is the only one program, as of today, that can browse X-T1 raw files on OSX!
Update: xnViewMP also supports X-T1 raw file browsing.