Any thoughts or recommendations would be much appreciated.
what goes towards X-T1 ?
1) you might like Fuji's ergonomics
2) Fuji, albeit no Kodak, has a long history of dealing with colors - so you might like Fuji's colors (OOC JPG)
3) Fuji now has a good lens selection and you might like their lenses better
4) sensor is bigger (1.5 crop vs 1.9 crop of E-M1) - so, as there is no replacement for displacement, above deep shadows S/N is around 0.5 stops better, that simple based on a bigger light gathering sensor size - however in deep shadows (= DR) X-T1 does not perform much better (in fact noticeably worse that XE-2)...
5) sensor is bigger so things like DOF, etc are ~1/2 stops better
what goes towards E-M1 ?
1) you might like Oly's ergonomics
2) Olympus, albeit it has no history with films like Kodak or Fuji, still is not in the last place colors-wise
3) m43 has the biggest native mount optics selection
4) some people do like IBIS
5) flash, shutter & x-sync = 1/8000 & 1/320 (1/250 remote optical TTL), remote optical TTL exists, HSS naturally exists - while Fuji is 1/4000, 1/180, no remote TTL, unnaturally no HSS for Fuji...
6) Olympus does not have issues related to x-trans demosaicking
7) you can switch to Panasonic m43 cameras while keeping lenses & flash - may be you like video, there Fuji is simply a non player.