I have both cameras, I thought it might be a good idea to keep hold of my X-E2 body and sure enough, now fw 4.0 is available, I'm really glad I did.
It occurred to me that the two cameras are now not so different to each other, so I started putting together a comparison spreadsheet of specs, using the latest fw versions for both cameras.
Hopefully, if you're in two minds about whether to keep your X-E2, upgrade to an X-T1 or maybe even buy a second-hand X-E2 instead of an X-T1, this might help.
Let me know if I got anything wrong, but I did most of this using the info on Fuji's website so it should be accurate
https://docs.google.com/spreadsheets/d/1NT0gidgtP6nT7681vRpSJgh34ShverMhbqycOZGydCs/edit?usp=sharing
Dave