I’m going to skip the whole back-story here and get straight to the meat: Don’t waste your money on an EOS R5 or R6. Instead, spend your money on the best mirrorless camera with the greatest value. the EOS R.
The reasons are many. First and foremost, the EOS R is cheaper than the R6 and way cheaper (by several thousands of dollars) than the R5. Secondly, it does almost as much as the R5 and R6. If we’re talking about megapixels, it actually does quite a bit more than the R6 – nearly 10 MP better. It shoots 4K video, it takes amazing photos, it works with all of the same lenses, it has extremely low noise levels. To put it bluntly, the R5 and R6, while both amazing cameras, don’t really offer a massive upgrade in terms of features for your average pro-photographer to warrant the huge increase in price.
It drives me crazy when I hear people talking about getting an R5 or R6 without even regarding the original EOS R as an option. Here’s a quick table to illustrate my point.
| EOS R6 | EOS R | EOS R5 | |
|---|---|---|---|
 |  |  |
|
| Camera Format | Full-Frame (1x Crop Factor) | Full-Frame (1x Crop Factor) | Full-Frame (1x Crop Factor) |
| Sensor Resolution | Actual: 21.4 Megapixel Effective: 20.1 Megapixe | Actual: 31.7 Megapixel Effective: 30.3 Megapixel | Actual: 47.1 Megapixel Effective: 45.0 Megapixel |
| Image Stabilization | Sensor-Shift, 5-Axis | Digital (Video Only) | Sensor-Shift, 5-Axis |
| ISO Sensitivity | Auto, 100 to 102400 (Extended: 100 to 204800) | Auto, 100 to 40000 (Extended: 50 to 102400) | Auto, 100 to 51200 (Extended: 100 to 102400) |
| Shutter Speed | Mechanical Shutter 1/8000 to 30 Seconds Electronic Front Curtain Shutter 1/8000 to 30 Seconds Electronic Shutter 1/8000 to 0.5 Seconds | Electronic Front Curtain Shutter 1/8000 to 30 Seconds Bulb Mode | Mechanical Shutter 1/8000 to 30 Seconds Electronic Front Curtain Shutter 1/8000 to 30 Seconds Electronic Shutter 1/8000 to 0.5 Seconds |
| Exposure Compensation | -3 to +3 EV (1/3, 1/2 EV Steps) | -3 to +3 EV (1/3, 1/2 EV Steps) | -3 to +3 EV (1/3, 1/2 EV Steps) |
| Metering Range | -3 to 20 EV | -3 to 20 EV | -3 to 20 EV |
| Continuous Shooting | Mechanical Shutter Up to 12 fps at 20 MP for up to 1000 Frames (JPEG) / 240 Frames (Raw) Electronic Shutter Up to 20 fps at 20 MP for up to 1000 Frames (JPEG) / 240 Frames (Raw) | Up to 8 fps at 30.3 MP for up to 47 Frames (Raw) / 100 Frames (JPEG) Up to 3 fps at 30.3 MP for up to 47 Frames (Raw) / 100 Frames (JPEG) Up to 2.2 fps at 30.3 MP for up to 47 Frames (Raw) / 100 Frames (JPEG) | Mechanical Shutter Up to 12 fps at 45 MP for up to 180 Frames (Raw) / 350 Frames (JPEG) Electronic Shutter Up to 20 fps at 45 MP for up to 83 Frames (Raw) / 170 Frames (JPEG) |
| Video Recording Modes | H.265 4:2:2 10-Bit UHD 4K (3840 x 2160) at 23.976p/29.97p/59.94p [170 to 340 Mb/s] Full HD (1920 x 1080) at 23.976p/29.97p/59.94p/119.88p [28 to 180 Mb/s] H.264 4:2:0 8-Bit UHD 4K (3840 x 2160) at 23.976p/29.97p/59.94p [120 to 230 Mb/s] Full HD (1920 x 1080) at 23.976p/29.97p/59.94p/119.88p [12 to 120 Mb/s] | MP4/H.264 UHD 4K (3840 x 2160) at 23.976p/24.00p/25p/29.97p Full HD (1920 x 1080) at 23.976p/24.00p/25p/29.97p/50p/59.94p HD (1280 x 720) at 25p/29.97p/50p/59.94p/100p/119.88p | Raw 12-Bit DCI 8K (8192 x 4320) at 23.976p/24.00p/25p/29.97p [2600 Mb/s] H.265 4:2:2 10-Bit DCI 8K (8192 x 4320) at 23.976p/24.00p/25p/29.97p [680 to 1300 Mb/s] UHD 8K (7680 x 4320) at 23.976p/25p/29.97p [680 to 1300 Mb/s] DCI 4K (4096 x 2160) at 23.976p/24.00p/25p/29.97p/59.94p/100p/119.88p [170 to 1880 Mb/s] UHD 4K (3840 x 2160) at 23.976p/25p/29.97p/50p/59.94p/100p/119.88p [170 to 1880 Mb/s] Full HD (1920 x 1080) at 23.976p/25p/29.97p/50p/59.94p [28 to 230 Mb/s] H.264 4:2:0 8-Bit DCI 8K (8192 x 4320) at 23.976p/24.00p/25p/29.97p [470 to 1300 Mb/s] UHD 8K (7680 x 4320) at 23.976p/25p/29.97p [470 to 1300 Mb/s] DCI 4K (4096 x 2160) at 23.976p/24.00p/25p/29.97p/50p/59.94p/100p/119.88p [120 to 1880 Mb/s] UHD 4K (3840 x 2160) at 23.976p/25p/29.97p/50p/59.94p/100p/119.88p [120 to 1880 Mb/s] Full HD (1920 x 1080) at 23.976p/25p/29.97p/50p/59.94p [12 to 180 Mb/s] |
| Focus Type | Auto and Manual Focus | Auto and Manual Focus | Auto and Manual Focus |
| Focus Mode | Continuous-Servo AF (C), Manual Focus (M), Single-Servo AF (S) | Continuous-Servo AF (C), Manual Focus (M), Single-Servo AF (S) | Continuous-Servo AF (C), Manual Focus (M), Single-Servo AF (S) |
| Autofocus Points | Phase Detection: 6072 | Phase Detection: 5655 | Phase Detection: 6072 |
| Autofocus Sensitivity | -6.5 to +20 EV | -6 to +18 EV | -6.5 to +20 EV |
| Viewfinder Resolution | 3,690,000 Dot | 3,690,000 Dot | 5,760,000 Dot |
| Rear Monitor Resolution | 1,620,000 Dot | 2,100,000 Dot | 2,100,000 Dot |
| Memory Card Slot | Dual Slot: SD/SDHC/SDXC (UHS-II) | Single Slot: SD/SDHC/SDXC (UHS-II) | Slot 1: CFexpress Type B Slot 2: SD/SDHC/SDXC (UHS-II) |
| Wireless | Wi-Fi Bluetooth | Wi-Fi Bluetooth | Wi-Fi Bluetooth |
It doesn’t take a lot of looking before you realize just how closely these cameras perform in nearly all aspects. The R5 is the clear winner when it comes to video format and quality, and both the R5 and R6 are better burst-photo cameras as well. But the EOS R outperforms the R6 in the megapixel department handly. All three cameras are said to autofocus well in pretty much every situation.
You may come away with a completely different conclusion but it seems to me like the clear winner for quality versus cost is the EOS R. The one exemption might be if you are a wildlife or sports photographer who needs the extra speed offered by the R5 and R6’s upgrade DIGIC processing power.