Re: Most who have tried it, say the same thing
Sadly every system has something what prevents me from to pick it up.
Samsung: Why probably it would be the easiest to just stay at Samsung and buy an NX1 next to my NX500 but still it is a dead system.
Fuji: While the XT-2 seems like an awesome camera: Great AF system, weather sealed, good frame rate and buffer size. But you basically have to buy a battery grip too. Also you can't also you use log if you don't have an external recorder. Which is cool if you only interested in video. But I often go to convention where I do both photos and edit music videos. An external recorder would just slow me down.
Panasonic: While GH5 looks like is going to be an awesome camera. (also the g80 is a nice one too). It will have a huge problem. It is still a Micro Four Thirds so the low light performance is probably going to be bad.
Canon: While I read good reviews about its new M5 but as I can see it is still miles away from Sony, Fuji, Panasonic and Samsung.
Sony: It is a little more complicated. I definitely would pick 6500 over 6300. Not only because it seems it has less overheating issue but also because it has in-body image stabilization. I know the touch screen is not perfectly integrated but I barely use touch screen even on my NX500 (Even for focusing - I am more of a focus-recompose guy). The only downside is the awful rolling shutter. Which is just look tragic. Of course they also have the full-frame mirrorless and the SLT series. But both series has some really annoying feature.
Olympus: Again Micro Four Thirds. So it has the same issues as the Panasonic.
Nikon: While they didn't really do mirroless cameras. I guess I could pick up something like the D500 which seems like a good camera but also nothing really special. It hasn't got any particular weakness but also not any unique strength.