For you , considering that you mostly do stills and (if I understand correctly...) the video would be for wildlife, your Canon rig will probably do a better job.
Having dealt with pro photographer from both the Canon and Nikon camp (as well as the fewer from other brands...) I do understand the importance of familiarity and being at ease with a particular brand.
My likes and wants (I have no "needs" here) are different, so I am looking at it from a different perspective.
To really have a better opinion (I am just ,like everybody else, speculating at the moment) I need to have the camera in my hands and shoot something.
I was a bit puzzled by the colours in that Sony clip, but it is a you tube clip after all.
The rolling shutter bit is still to be determined, balance and ergonomics "look" better than with most/all DSLR rigs, editing (ease of, as well as transcoding) will be a major part of how it could work for me.
I have a basic understanding on how to use Premiere, have Vegas installed ( does not crash but can't be bothered to learn it) but use Pinnacle Studio, something that Koko the gorilla could master.
( I haven't yet, but can do some of it)
You would be amused to know that yesterday my Canon video camera took a tumble (on the carpet of my lounge room) when a leg on my toy tripod collapsed. Stupid twist lock thingo ( user error, after 30 years of selling tripods I should know better)
The camera is OK.