I am no professional - just an enthusiast who spends most of my time shooting wildlife.. When I sold my wonderful 1D X it was primarily to go mirrorless for the weight saving and so I did not have to drag my XA20 camcorder around as well. I was well aware there were sacrifices to be made and even better brand options for my type of shooting, but the cost of switching was just too high.
However the more I use this camera , so slandered by sooo many, the more I smile as I really see the value this camera is delivering - screen drag AF is the best change I have seen for years, low light focusing and exposure, stunning colours, so many features that help customise to your personal preferences etc. etc. Its not perfect but I for one am stunned on what this new RF system will allow ahead and how my past lens investments continue to deliver quality images and some aspects are even enhanced - using full range AF with extenders, adapters with brilliant filter features that can be used across so many lenses etc. etc.
In summary if Canon move on firmware as the other brands appear to be forcing them to do, we will all be winners ahead - the small form block with servo AF will be a real boost for me - now if only the two changes could be at the 8fps high speed option...... (but that's probably beyond this models processing capability).
Still at the end of the day my ugly duckling is blossoming and if you have seen some of the recent professional videos using the EOS R such as Jason Laniers Death Valley shoot you would probably agree with me that the real improvement that 98% of us need is on the use of what we already have!