I first got the XE-1 then the X100s and offloaded my 5D Mk11. I was to travel to Australia for 2 months and I could not bear the thought of lugging around a heavy body with an assortment of "L" lens's
Truthfully, had I got the X100S first, the XE-1 would not have had a look in.....and I would have kept the 5D Mk11
I have to say, the X100S is an astonishing camera. I know they say it is the person behind the camera that makes the difference, but the camera does have to be capable of translating your vision. It does that in spades. The IQ is fabulous and I believe it is very very close to being equal to anything produced from a full frame Canon or Nikon. It is a great street shooter and the 6400 ISO in low light is very, very useable. In fact, you could use it all the time.
I have done street, landscape and cityscapes with it and it never lets me down. One key thing about the retro look? Doesn't look threatening for street work. You can tuck in close, no noise shutter....bish, bash, bosh. Job done.
As an accompanying camera to your Canon (in whichever iteration......mine is a 6D) it will surprise you and you will love it like you have never loved a camera before.