I got my Z20 last week and I shot this motocross practice Saturday afternoon with a combination of 4K @ 120 fps and HD @ 240 and 180 fps. But if I had to to it over again, I'd just stick with 4K. I don't think the HD footage holds up as well.

https://youtu.be/7iJlUGy7_YA?si=OWZoUvar_dmXEJWy