Well it does add this, given my experiences on Canon's other mirrorless:
- Ability to purchase and actually use Rokinon/Samyang fast primes using focus peaking/5x zoom in the viewfinder
- Continuous fast AF with STM lenses when continuous AF is turned on
- Flip touch screen, with the 5D4 lacking the tilt option
- Ability in the future to actually pick up RF lenses and use them
- Silent shutter (unless silent shutter is buried in some other automated setting like on the M50, rendering it basically useless)
- With an adapter, be able to use EFS lenses
But if doing sports or fast AF tracking, it wouldn't add anything, or expecting some sort of high ISO or low ISO DR improvements, which will be nothing or negligible at best.
I"m headed for this EOS R or the Pro Version. But my thoughts have been tracking various direction after just selling my 5D mk iii and keeping my 5DS. I questioned whether maybe to go with a 1DX mk ii. But then I remember I pulled the battery grips from both FF cameras months ago to shed size and weight. So that culled my thought of the 1DX mk ii. Then I'm debating whether to get the 28-70 to replace my 50mm 1.2 EF and 24-70 2.8. But I paused on that thought due to the same weight reduction goal. The new RF zoom weighs more than the Canon 70-200mm 2.8 IS.
But everything still brings me back to seeing the EOS R and RF the direction to INCLUDE. From what I've read about it's focusing ability in low light when needed, it sounds like it outperforms the 5D mk iv or 5D mk iii I had. Or my 5DS. My most challenging thought will be do I keep the 5DS or convert it to a 5D mk iv. And, what lenses to keep or change. Presently, I have my Zeiss Milvus 85mm for sale due to a change in my right vision. But unexpectedly, the EOS R's little converging triangles for manual focus compensate, and maybe it's worth keeping the Milvus now.