Coming from the 5D IV, my only doubt, which is probably also your doubt, my friend who is reading this, was the 20MP. Don't think about it, press the shutter button and give yourself the best gift, as well as to your old EF lenses.

The new autofocus of the Canon is unbelievable. It will truly leave you speechless. I had done micro-adjustments on all my lenses at a well-known store, and no matter what I did at 1.4 and 1.8, it always required several attempts and a specific distance from the subject to achieve that 100% sharp photo.

Now, it's always wide open unless I intentionally want to show more focused subject. Not only is the 100% focus percentage fantastic to the point where you take fewer photos because it comes out perfectly on the first try and you don't have the anxiety of taking another click just in case, but the multiple focusing modes now unlock creativity. The framing is better, fewer "missed" moments, and clicks that come out effortlessly, while with a DSLR, if you weren't "specialized" in something (e.g. bird or action photography), there was no chance of getting a good shot...

Let's go back to the hot topic... "Megapixels." The file produced by the camera is so good that even if you crop it to the opposite orientation and reduce it to 8-9MP, for example, if you turn a vertical photo into a horizontal crop because you didn't capture the alternative and it looks nice in your edit, it can be printed easily at 50-70 centimeters. If, despite all this, you still fear extreme cropping, you can open the photo in the new Photoshop and open it in ENHANCE 4X Super Resolution, and... voila! It becomes 30MP+ and even sharper... yes, it happens somehow magically with the help of AI. If that's still not enough for you, you can spend $70-90 and buy TOPAZ GIGAPIXEL AI, where the file can be enlarged up to 6 times with higher resolution... I know it sounds crazy if you don't know about it, but it's now a reality, not just in crime movies!
Tutorial - test by the amazing Karl Taylor for both tools:
https://www.youtube.com/watch?v=MtPsCHtJ7bQ

The camera grip is simply perfect, exactly what it should be. Smaller body, bigger grip. Slightly lighter than a DSLR with the adapter, but even that little difference becomes noticeable after a few hours in your hand. I imagine without the adapter and with RF lenses, the experience will be even more perfect, but I don't have any yet.

The new battery didn't bother me. With just one cycle, it easily takes around 400 photos until it reaches half capacity. It also depends on the settings and how each person uses it, of course.

I would have liked it to be made entirely of magnesium, but the construction still seems sturdy. It's definitely not the same, but it's not a cheap or fake body. However, it's not R5 / 5D IV.

I hardly ever used the top screen "substantially." Okay, because it was there, I might take a quick look to see what settings I had, but that's about it. I think the extra dial is much more user-friendly than the R5's screen.

The screen resolution didn't seem degraded to me coming from the 5D IV. It probably has the same PPI, which is what matters to us, regardless of whether it's larger or smaller. However, it's clearly visible what is in focus.

They say the EVF is better than the R5's, and indeed, when you first look at it and if you have it on "battery saving" mode, which doesn't have the max refresh rate, it gives you the feeling that it has a low refresh rate. You notice it, but personally, it didn't "dizzy" me. It seemed a bit strange to me. It's very smooth at high speed. I just put it on for a test and then switched back to normal. Since then, my eye has simply gotten used to it and it looks comfortable and relaxing, even in "normal" mode. Anyway, with the capabilities that the focus and detachable screen give you, many times you forget to use the EVF :)

The simultaneous BT-WIFI connectivity is an incredible convenience. Yes, I envy the R5's 5G, but at 20MP with much smaller files, it may not be necessary, while the 2 SD cards instead of CF will be much more useful to me.

As a professional, I decided that the disadvantages of having to take all your photos at 50MP are more than having to take your photos at 20MP and missing out on the extra resolution in less than 5% of the total photos you take, which the software can ultimately provide a solution for. It's amazing that you can have a 50mm lens on and switch to crop and shoot at ±85 without really losing quality.

Canon knows. Don't worry about the MP, buy it and you won't regret it! If you're a professional who needs to print in a large size, first download some RAW files and try the tools I mentioned above. You may not need to go for the R5 after all, but if you do, you'll have the same camera after a testosterone injection :)

P.S. It's a big issue that no image editing program supports native camera profiles. It's really unbelievable that you can't get the colors you see in the camera when you open the photo in PS, Lightroom, Capture One, etc... Be prepared for extra editing with R5-R6 until Adobe creates the color profiles. I have a solution for this too, although I don't use it:

https://www.canonrumors.com/forum/threads/color-fidelity-r5-profiles-are-a-game-changer.39441/
https://www.colorfidelity.com/

Update after 2 months:
1) The new RF lenses are simply incomparable in terms of quality. As the owner of the 35mm 1.8 RF, I can say that the sharpness levels are on another level compared to the EF lenses. With such results from essentially an entry-level lens, I can only imagine what it will do with an L RF lens... 100% focus hit with the 35mm without any effort. I've taken one back-focused photo that I can't imagine how wrong I was.
2) The battery easily lasts over 1000 photos with maximum brightness on the rear screen and auto, I think the viewfinder is set to normal refresh rate. I think it turned red around 1400 shots.

Update on June 13th:
The RF lenses have no comparison in performance with the EF lenses on this camera. Even the 35mm 1.8 is razor-sharp. The adapter works 100%, there's practically no difference in focusing speed, but the technology is simply different. Even the bokeh has a different quality. The EF 50mm 1.4 USM, even at 1.4, you have to make a mistake to lose focus or there has to be movement in the subject and the focus slightly shifts, but even then, the photo is "pass," meaning it just gets that dreamy look of wide aperture. But while everything is creamy behind, while it's 1.4, the level of sharpness and focus of the RF lens is not there...

After quite some time now and with Lightroom incorporating the enhance option within the program, I have to say that I feel very lucky that I made the right decision and didn't get involved with the R5 files. R6 for the win, unless you're a videographer and want the extra goodies, then go for it.

update 5/10:
Now the owner of the 24-70RF L and 70-200RF L lenses.
100% hit rate and incredible frame rate. In the Acropolis rally with the 70-200 x1.6, it's practically like shooting video from the frames... you have the entire sequence frame by frame, as if exporting frames from a video. It's unbelievable.

I also tried the Color Fidelity color profiles. I can say that with minimal adjustments or even sometimes none at all, the result is almost identical or identical to the camera's. Obviously, it's unacceptable that Adobe still doesn't have the proper camera color profile. From what I've seen in similar software editors like DXO Photolab, the colors are normal as shown by the camera. Shame on Adobe...

I would also like to add that now I really think I would have made a big mistake if I had bought the R5 due to the huge file sizes and the lack of 2 SD slots. The only thing I would change is the wifi module, which is not wifi6.