Wow what a day has made for me. So many emotions. When I first saw the announcement, my first post on here referred to the R5C as "junk". Of course I said that in raw emotion, and the R5C is quite a feat of engineering in general, although I am still disappointed at the same time.
Looking at all the hands-on videos last night, I think I do have a better understanding as to why Canon went with a fixed sensor vs floating sensor. And I have a much greater appreciation for what Canon has done in creating two independent video and photo environments - I do believe this is the way. While it may take time to switch over between the two environments, I don't think it will be hard for Canon to offer a future firmware update that would allow someone to take a photo from the video environment (apparently this can already be done) and vice-versa- taking a quick video from the photo environment. If not in this camera, I do see it migrating into other hybrid C cameras.
I do see Canon selling a lot of these. These cameras look very beautiful from the front, with the red accents - almost like the Ferrari of Canons. But the sideview - god that chunky side view!!

Theres a level of refinement that I would expect in every Canon model - I've often felt that Canons are so well designed that you hardly feel them in your hands. I still feel that this particular design is more unrefined - partially as this is Canon's first efforts in installing/designing a fan for a ILC body, and partially due to the limited time to get this camera to market?
I do see potential in a R5 Mark II eventually containing a better, more optimized heat management system to manage 8K workflow in a far better manner. I also see a potentially more refined R5C coming out that will have a far more refined design and updated features. I could also see an R1C along the way should Canon see success in these offerings.
For me, my issue is that the lack of IBIS will almost certainly prevent me from optimizing the run-and-gun video that I want to perform, while also still possessing a full-fledged photo camera. This video below demonstrates some of the micro-jitters that you'll see if you handhold this camera without a gimbal:
Of course a gimbal can correct all of this. But for me and how I wish to use this camera, I think taking a gimbal everywhere I go would be overkill, and theres lots of events where I cannot take a gimbal. For those in professional videography who take controlled video, I think this will be a very strong product. But for everyone else, its either the R5, or just wait for a future model.