SONY doesn't appeal because, as Godfrey described, it's clunky. I wouldn't enjoy a camera with those ergonomics. SONY seems to spit out new products all the time.They just seem unstable to me. Perhaps it would be more accurate to describe their marketing philosophy as too dynamic. Obviously I am not interested at all in videography.
The OVF on the Fujifilm bodies is enjoyable. It's not that tricky to set the camera up such that it's operation is minimalistic and simple. The X-T1 EVF is well... an EVF. There are many generations of EVFs and the newest technologies outperform the older ones. For commercial work I prefer the EVF to DSLR OVFs. For action photography EVFs require anticipation and shutter bursts. DSLR OVFs are superior for action. For candid work I prefer the OVF. But with practice the EVF is not limiting.
The APS-C sensor size is not a significant handicap because the Fujinon lenses' focal lengths mean you can use the system just as you would use a 24 X 36 mm system with traditional focal lengths. Those who require the shallowest possible DOF and work in extreme low light will benefit from the increased sensor area.
Otherwise the physics of
equivalence applies. Equivalence is a controversial topic due to its complex nature. It's relevance is even brand dependent because read noise is brand dependent. Equivalence levels the playing field for m4/3, APS-C and 24 X 36 mm camera bodies. This is especially the case for cameras with ISO-invarient data streams.
For me, after using film lens lenses with APS-C sensor bodies and 24 X 26 film and digital bodies, I did not enjoy using the APS-C bodies. I honestly feel differently when using lenses designed for APS-C sensors. However I don't curate lenses. I'm sure I'd think about sensor area quite differently if I had an emotional attachment to lenses I acquired and enjoyed over decades.
The Fujinon lenses are one the three reasons I am, and will remain, a Fujifilm owner. The second is I can simulate (not duplicate) the RF usage experience. Third, the Xtrans data stream's signal-to-noise ratio meets all my needs. I have no issues rendering the raw files. In terms of making progress on my projects, the Xtrans sensor is neither a positive or negative factor.