I am and industrial photographer who shot medium and large format film. But for fine art portable work, I bought a Leica and two lenses. until a few years ago, I shot all Nikon digital, because I had so much Nikon Glass, was locked into their system. A Contax friend talked me into the X-Pro 1 and two new hi end zooms for my fine art, 10-24, and the 18-135. both produce great images. But when I tried shooting my grandson's little league games, the camera wouldn't focus fast enough. I ended up purchasing the Fuji X-E2 with their very fine 18-55 lens (also a Sunwayfoto L-bracket/grip). This camera is heads above my favorite X-Pro1 for focusing, and hand held work. I think if you use the fast prime X lenses, you will find this might be the answer to your needs. the only draw back I have found (besides no tilting LCD screen) might be the flash system (perhaps Metz might have a flash that works). I shoot homes for builders and realtors, so I shoot off camera flash units fired with a radio control. yes, I think Sony would be my second choice, but don't underestimate Fuji. they might be slow getting up to speed with the competition, but when the do, it is usually a very fine product, which is why Hasselblad had them make some of their cameras and lenses.
On another note, Hasselblad has a modified Sony full frame DSLR (I know its heavy and larger) camera that they were selling for $12,000. since they couldn't give this camera away, B&H has been trying to sell them for $3,999, with a very fine 12-70mm 2.8 lens. Even though it's a Sony, dressed as a Hasselblad, it means that Hasselblad probably tweaked this camera to the highest specs. which means this might be a great all around one lens travel camera if you don't mind the size