The RX100 and RX10 both do pretty well in video mode AF. The face detection is VERY good, and if you're looking for more scenic stuff "wide" focus hasn't let me down. In low light situations it isn't going to blow your mind, but as long as there is some contrast on your subject you should be fine. I threw together a little video of the RX10 mkii HFR modes. The quality is pretty much identical to the RX100 mkIV. I'm beyond impressed:
Threw together this video last night. My first time properly editing a video! At any rate, I was absolutely floored by what this camera can do. All shot in SLOG2 and graded using one of the Fuji filmstock effects. The HFR focus/display behavior is infuriating, but I was able to eyeball focus and mark the placement of the matchbox. Hope you guys enjoy.