I own the following - XF100, the GFX and the Nikon D810. The XF100 is my go to camera but I always take with me the 810 as a backup. For my work, I almost always use a tripod - 95%+. For me, the files of the XF100 are much more workable than either the GFX or the 810. Additionally, I like the extra pixels when I need to crop as I often like a square format - it just gives me more flexibility. I do print large so that is a factor in my decision. After shooting some with the GFX I don't see a huge benefit over the 810. BTW, I bought the GFX to use when I didn't want to carry the heavy XF100 system. From a user interface perspective, I find the XF100 to be the easiest camera to operate with the 810 coming in second. I really don't like the GFX interface. At the risk irritating a bunch of people, purchasing the GFX was a bit of a mistake for me. Not because of the file quality but the incremental quality above the 810 is only marginal. I have never shot 8x10 but if I had I likely would have done it to give me the best quality info to work with. Other than cost, I can't image why you would choose a 50mp system. Just my random thoughts!
