Fastest Motion Sensor?

looking for the fastest affordable motion sensors to connect to my smart hub

I bought used Iris iL07_1 off eBay for around $12 each. They paired with no issue, are responsive to motion, report temp and humidity, and have great battery life. If I needed more motion sensors, I’d definitely buy more of them.

Indoor or outdoor? Outdoor is a very limited set of options.
Mounted on wall or ceiling? The lens of a particular device may be optimized for motion along one axis.

My gut feel is that you would want one that executes locally, versus cloud. That would exclude the two that I currently use (Hue outdoor and Sonoff ZigBee).

If local is a requirement, then Iris is out. It is cloud-based. I have been happy with the Samsung motion sensor I have too. It is reasonably quick, with great battery life, and executes locally.

The Sonoff Zigbee runs local if you use the Smartsense Motion dth, and it’s $15.