The FUJIFILM X-H1 which offers 120fps 1080p slow motion was a worthwhile effort to offer high frame rates that are usable to their video-centric base. It still was not as good as the Sony or Panasonic slow motion options due to aliasing, moire, and noise but with a little post work, it could be used with success in an edited piece. FUJI then with a firmware update for their stills flagship the X-T2 allowed the camera to now shoot the same 120fps 1080p slow motion which makes sense considering they use the same sensor on both cameras.
The camera site CVP has done a full comparison review here which pits the X-H1 against the X-T2 to see which camera strengths are ahead on each body and if it makes sense for X-T2 owners who are invested in a FUJI lens system to upgrade. Their findings are interesting and as far as slow motion it is clear that while they use most of the same imaging pipeline; the X-H1 has the edge with less crop, less aliasing, and better artifact suppression when using the 120fps slow motion mode.