1DX III vs R5 AF

[Joel Eade]

Not trying to jump in for Fast Glass, but also to clarify if my assumption was incorrect. I took the question to be a comparison of the PDAF through the viewfinder and DPAF using liveview both on the 1DXIII.

Ah .... that makes more sense to me now. With mirror up in live view the 1DXIII is functioning like a mirrorless camera but instead of contrast detect focusing like many prior cameras used in live view it is using DPAF.

I also wonder if the more powerful battery in 1DXIII has any effect on how fast it can achieve focus in terms of physically driving the lens faster?