My experience has been very good with two Sigma lenses and AFC (Area+ Human/Animal detect on) for video recording. Both 4K 60P 10-bit 422 and 5.9K 30P 12-bit RAW (both to external Atomos Ninja V).
The two lenses I use are:
1. Sigma 14-24mm DG DN f/2.8 Art - Firmware updated to version 1.3
2. Sigma 24-70mm DG DN f/2.8 Art - Firmware also updated to version 1.3
Panasonic Lumix S5 is currently on firmware 2.4 (some bluetooth fixes since version 2.3, no AF changes mentioned in release notes).
In a variety of lighting situations, I'm able to move from subject to subject and have the focus work well to my expectations. This is even when at 70mm.
Linear focus support in MF was also added to the Sigma lenses with this firmware update. You still need to use a USB L-Mount dock and the Sigma optimization software to adjust the focus through (runs just fine on my 14" MacBook Pro M1 Max, so the software is Apple Silicon compatible). The dock is not needed for firmware updates, you can do them in camera just like Panasonic lens updates. In addition, the default Linear MF is good, so adjusting it might not be necessary for most.
For those that have the lenses already, try updating them and giving the AF another test.
As for photography, these are excellent as well.
