I, like many, am a big fan of Bryan's work over on TDP. One item he has added toward the end of his reviews is a discussion regarding alternatives to that product. If you go toward the end of the
R5 II's review page, you can see that he considered the R3 as an alternative to the R5 II.
But, to quote, advantages of the R3 over the R5 II include:
- "Supports high-speed continuous shooting for 150 RAW images vs. 93
- Custom high-speed continuous shooting supports higher frame rates
- Up to 1/64000 shutter speed vs. 1/32000 (crazy fast vs. extremely fast)
- Smart Controllers (powerful controls after some acclimation)
- 4.15 million dot LCD vs. 2.1 million
- Integrated vertical grip, LAN port, and GPS (outstanding grip ergonomics, the grip, port, and GPS are available accessories for the R5 II)
- Superior dust and weather resistance (with both bodies significantly sealed, will we notice the difference?)
- More controls and buttons (these make the camera faster and easier to use. And, more complicated?)
- More powerful 2750 mAh LP-E19 battery pack vs. 2130 mAh (but the R5 II holds 4260 mAh in the vertical grip)"
I think the integrated grip alone will make the R3 appealing to some people at the same price point. But, birders will always want more MPs. I suspect Ron from WWP ends up with two R5 IIs. Bryan at TDP, who shoots a lot of wildlife, is going with two R5 IIs.
In terms of the R3, between the R6 II/III, R1, and R5 I/II, there really is not much of a market, IMO. If they come out with a R3 II, I expect something will have to be significantly different and while many will point to higher MP as the obvious differentiator, I suspect the gripped R5 II is Canon's answer to a larger body 45 MP camera. Pushing higher MP runs into an issue of bandwidth at higher frame rates.
So, I agree, I think the R3 is a one-off. It served its purpose.