I've been doing a fair few tests the last few days as I work out which direction to go in for my professional work as far as investing further in a system (not a brand loyalist at all but I love pretty much everything about the X-series). I've always assumed the Sony A7 series had better image quality, but wanted to be sure rather than go on gut feeling before I invest in a bunch more lenses (obviously prefer the feel and ergonomics of the Fujis).
These results are obviously subjective to my workflow. I use lightroom, it's perfect for me and not interested in any other raw converters. VSCO is also a big part of my workflow.
The results:
Sony wins
• Detail, thanks to the extra megapixels and lightroom still having the 'waxing' issue with Fuji raw files for fine details like brickwork etc.
• Highlight roll-off - something extremely important to me for subtle changes in skintone that tend to sit near the top of the histogram.
• Colour Depth, it's a subtle difference but noticeable in the red channel and skintones again.
• Iso, both are pretty shithouse from 3200 and up from my point of view, but that's all I really need anyway. The Sony has a slight edge in the mid-isos from 1250 - 2000. Hard to explain, but the Sony seems to cope in poor, flat light better in my experience, whilst the Fujis really need good light to shine (not always available on quick location shoots).
Fuji wins
Dynamic Range by a solid margin - you really have to push your luck to get either of these cameras to blow out highlights or clip shadows, but for me, the x-t1 had an edge, at any iso (see top windows in screenshot).
Obviously there are a whole new generation of Sony A7s that probably kill the X-T1 for dynamic range, but the value plus the lack of native lenses available means I'll be keeping my X-T1 for work stuff as well as play for at least another year. I could still be tempted by the cropability of the Sonys though. Looking forward to the improvements that the next gen of X-Series bring too.
Also worth mentioning that you can buy the 56 and 90mm for the price of the batis 85mm if you shop around.
In conclusion, all I've really learnt is that no camera or system is perfect and if you're looking over the fence, you're just distracting yourself from taking great photos.