Some things, silent mode causes a problem with horizontal lines (see image). It shoots 4K video up to Max 10 and overheats or whatever it is and stops. Many times the lens does not communicate with the camera (it wears an adapter). Excessive crop in 4K, enough noise even with ISO 1000. Overall, I would easily return it.

It was purchased in early 2021 for professional use at €1500, including the original battery grip, with 80% of its usage for photography and 20% for video, initially as an experiment but eventually becoming my favorite body. I almost exclusively use it with an adapter and a range of EF-L lenses inherited from DSLRs.

It has already captured 100,000 photos and 200 hours of video without any issues, even in harsh conditions.

The build quality is very high (no comparison to, for example, the a7iii), with a decent EVF and good battery life (easily surpassing the 5D by +25%). Your hard drives will love the compact CR3 format, and you will appreciate the fantastic touch menu/screen and, of course, Canon's great color reproduction.

It's not perfect, but it's a well-balanced proposition, easy to use (although a bit annoying in a couple of areas, it can be customized) and can reach the top in certain types of photography.

Obviously, it has ergonomic issues and "missing" features, which are covered by the R6/R5 but at a much higher cost.

Very good and high-quality machine! It goes beyond simple amateur use. With the appropriate lens for the type of photo you want, the machine is flawless! It has fast and good AF, fast and very powerful processor that can handle noise very well even in low light conditions. It feels very good in the hand although its weight is not the least compared to other machines. The capabilities and options it offers will allow an experienced user to make the most of every aspect of it. A very good choice for those who buy it. Its price is reasonable for what it offers.

I have been the owner of the EOS R for about 2 months. Upon receiving it, I immediately updated to firmware 1.4, so I didn't get to see it in its not-so-good phase. The camera has an excellent viewfinder (compared to the 7D2 which has the best optical), it is responsive with natural and clear image. Its autofocus performance is top-notch, and EF & EF-S lenses work better than the 7D. The single card slot is a flaw (definitely for professionals), and the extreme crop in 4K. Note for those who have EF-S lenses, when they are mounted on this camera, there is a mandatory crop factor of 1.6x and the resulting photos are 11 megapixels (out of the 30 megapixels the sensor has). This doesn't seem to happen when using lenses from other manufacturers, but below a certain limit, vignetting is noticeable. I shouldn't forget to mention the secure grip provided by the very good grip (comparable to DSLRs). And finally, an advantage is the LP-6n battery, which is exactly the same as all the double-digit EOS cameras, including the 5D and 7D models.

The machine is very good regardless of whether Sony is superior in the specifications.
I agree with most people who say that it is a machine that you have to try to understand if you like it or not.

The positives:
The EVF is fantastic
the body as a whole is excellent
the RF lenses are a different story on their own - the 24-105 kit lens is the best I have ever seen in a kit lens.
The EF lenses work maybe even better than if they were native
The colors of Canon
The battery is excellent (about 700/charge)
The menu is perhaps the best on the market
The screen is excellent
The curtain falls and covers the sensor when changing lenses (I can't understand why not all manufacturers do this)
The frame rate in servo is 6/sec which is sufficient for me

The negatives:
1. The issue of the huge crop in video when shooting 4K but personally I don't care because 1080 is more than enough.
2. The lack of IBIS in this price range (regardless of whether the lenses do a good job with IS)
3. The face/eye detection still needs work (Firmware 1.3.0)

The issue of the second SD that many complain about is not important to me because I am not a professional but I have covered it through the camera itself. Every photo I take automatically goes to my phone via WiFi (including raw files). There is a penalty in battery life but you can't have it all... (with what Canon does to us)

For this price, it is an excellent solution especially considering the prices and the number of lenses that Canon has.

*Update 26/9/2019: After installing Firmware 1.4.0, the eye AF has improved significantly and is now comparable to Sony's. The same happened with tracking in servo - it is day and night compared to the previous Firmware.

Something else I noticed (although there is no information in the release note) is that the touch & drag AF point selection has become much more sensitive and smooth - this change is very important as it was sometimes difficult to select the desired AF point.

Obviously, the camera was capable of functioning like this from the beginning but Canon did not pay attention to it or simply underestimated the issue.
Perhaps with a future firmware, Canon will decide to "unlock" the camera in terms of video (removing the crop) and Focus bracketing (which the smaller RP has). As I understand it, the camera has other capabilities that Canon has deliberately chosen not to provide.

*Update 2/10/2019: For anyone interested in charging the camera using the USB-C port and does not want to pay the $190 (!!!) that Canon asks for the PD-E1 USB Power Adapter, there is the option of purchasing the Anker PowerPort Atom PD1 charger which costs only €48.