I have shot a 5DII for the past four years. My backup was a 40D which I recently sold to a friend. I wanted to replace my crop camera but wanted something smaller. I had tried a NEX 5N but hated wading through menus. When I picked up the Fuji X-E1 and played with the controls I thought "this might work." There's a dial for almost everything you need for spontaneous shooting. Set the menus when you first set off to shoot and most everything can be adjusted in field with the three analog-type dials. So old-school, it feels very comfortable. And the size was perfect! When I looked at the first out-of-camera JPEGs, I was sold. They were almost as good as my full frame Canon.
I have since picked up a refurb 7D and after comparing the IQ with the Fuji, sent it back. No more noisy crop Canons for me. If I want to just take some "happy snaps" I grab the Fuji. If I have an event to shoot, it's the 5D plus/minus the Fuji. Much lighter combo than before. I can't speak to the SL1, but I've stopped looking for a CSC/mirrorless solution, because I feel I've already found it. If I had it to do all over, though, I'd definitely pick up an X-E2 for the speedier AF.