Personally I think that anyone heavily invested in a either Canon or Nikon it's a no brainier to be get the relevant mirror less offering if they are after a mirrorless camera, let's face they any camera produced in the last 10 years is capable of producing stunning work.
It's people who have a few lenses who in my opinion who are more likely to switch systems so why wouldn't a Canon shooter who fits in to this criteria look at the Nikon and vice versa. I know if that was me I would be looking at all the options.
I'm all in favour of different systems getting talked about in camera threads I know if I was in the market I would be reading theses threads and the more info the better.
People take photographs, not cameras. Absolutely agree that any camera from any manufacturer in the right hands is capable of taking great photographs.
Choosing a camera or system isn't just about image quality any more though and hasn't been for a long time. It's about finding something that best suits what your needs/wants are and there is no such thing as the perfect camera.
For me personally I wanted a mirrorless system as I liked the evf and the ability to see the exposure and depth of field before taking hitting the shutter button.
It then came down to a choice of the current options that are available. I held of deciding until Nikon & Canon's specs for their new mirror less options where released before making a decision on what suited me best.
It took some persuading for me to ditch Nikon after the best part of 20 years but there mirrorless option just didn't suit my requirements.
It would have been easier and much cheaper to stay with Nikon and keep the lenses etc. that I already had but the one card slot thing killed any chance of staying with Nikon stone dead straight away so it absolutely isn't a no brainer for everyone to just stick with Nikon or Canon.
I could have made the decision just to stick with what I had which worked well until Nikon eventually offered the same advantages as the current Sony options, but that would have mean't waiting possibly another 1-2 years and that wasn't something I wanted to do.
I was especially disappointed in the Nikon offering as it really brought nothing new to the table at all. At least Canon to be fair to them, have some exciting lenses and added a few new features like the shutter closing when changing lenses. Neither of the Canon or Nikon offerings offered anything like what I wanted from a new camera body. The Sony options came closest for what I wanted so I jumped ship to them.
I can't see any advantage for anyone that choose Nikon or Canon mirrorless over Sony other than ergonomics are better and it may be cheaper in terms of being able to use there current lenses via an adaptor.
