I have captured several dozen frames with Nikon glass on an X-E1 using this adapter. Not a single shot was in acceptable focus. None. I tried my darnedest to focus properly using the latest Fuji focus peaking. What appeared perfectly in focus during peaking shifted out of focus when the shutter release was half pressed, appearing this way in the finished capture.
Aperture control was so crude as to be useless. Stopping down afforded only marginally better sharpness at considerable loss of speed.
This was wasted, wasted money. Duct tape strapping your Nikon lens to an X body will be just as effective and less costly.