Okay here's a word from a Fuji Fanboy ...
Mike, for me all the different manufactures no longer matter. Nikon, Canon, Olympus, Pentax, Sony, Panasonic ... for what I shoot and how I shoot ... the camera body no longer matters. Again, for my tastes and in general, what I shoot and how I shoot, there isn't a significant difference in IQ between a modern FF, a modern APS-C and a modern MFT that will change the level of success of my images. (Of course there are always exceptions ... but I am speaking in generalities.)
I had this epiphany last week when I was walking around my camera store, thinking about all my images, my stuff and I realized that I pretty much captured the same level of photographic impact, the same level of success with my FF system, as with my MFT system, as with my APS-C system.
My experience is that at ISO 1600 and under, up to a 11x14 or 16x20, you won't see a significant difference between a 16mp sensor, a 24mp sensor or a 36mp sensor. If you need a computer to see a difference ... then that's no difference at all in my book. (For what I shoot and how I shoot a little more dynamic range, a little less noise, et cetera ... doesn't matter.) For me, after a certain baseline of IQ, the need for more/better IQ starts dropping like a lead balloon ... it is all about image impact. It is the composition, subject, perspective, lighting, exposure ... the matching of what I captured to my previsualized image, is what matters the most. (Now if I shot a lot of landscapes, architecture, commercial/studio, tripod stuff, I may have different thoughts.) But for the most part, I shoot people, people doing stuff, people in their natural environs, Street people, active people, people performing ... for me the whole world is a stage.
I've lugged around bags of Nikon film stuff, motor driven F's, FTn's, F2's and F3's around the world, through swamps, jungles, tundra, deserts, mountains, big cities, godforsaken rural areas ... (Hell, I've even slept with them), ... and I never complained once on size or weight. To me it is what it is ... if that is what I have to haul around to get the job done ... well, and again, it is what it is ... all part of the job. When I went digital, I went Canon and ended up with 1D's ... big ugly, heavy suckers. Again, I took them everywhere. My thoughts were, if there is a picturing worth taking, a moment worth capturing ... I don't want to compromise the capture with a substandard image/camera. dSLR's are still better for sports/extreme action. But the more I use mirrorless, the better I am harmonizing with the AF, the higher I am getting on the learning curve and the better I am getting at shooting action. With action, I am working harder and I am getting less keepers with mirrorless, but I am getting enough good stuff that I am not switching back to my 1D's. (And like Sten, I shoot a lot of theatre performances and I find my XT1's to be easily up to that task. But we all see differently, we all shoot differently and after viewing Sten's images, I suspect Sten has a higher bar and expectations for his images than I for mine.)
But, (the big but), time marches on and forward. These modern digital cameras All take one hell of a picture. Fuji is good... no ... Fuji is great, but so is Nikon and so is Canon and so is Olympus, et al.
For me, there are two things that matter, the system behind the camera: are there the quality lenses to do what I need to have done and IQ: I need the IQ to be sufficiently high to communicate without being overly distracting. Comfort, how the camera feels, where the button and dials are ... isn't important to me. Most/all modern cameras are designed to the average human hand and over time I can adapt. Fuji is still light on lenses, especially long and fast. But all the XF lenses are exceptional, and at a minimum, equal to my 'L' lenses. As for IQ, see above, in the early days of digital IQ was important and there were significant differences between cameras, but I really don't see that anymore.
But above all, what does matter is that you shoot. While weight and size is a secondary consideration for me, I certainly do appreciate the smaller size of mirrorless systems. The faster Fujinon APS-C lenses are large and heavy, but they are still significantly smaller than an equivalent FF dSLR system.
PS- I dunno if you can return the XT1, but if it were moi, I'd give serious consideration for waiting a weeks for the launch of Fuji's latest and greatest camera, the X-Pro2.
