The FP2 is the sensor everything else in this list gets measured against. One unit covers about 40 square meters and can track up to five people at once, and you can draw up to 30 zones in the app. That means a single FP2 in an open plan living room can tell your couch apart from the dining table and the desk, and run different automations for each.
It connects over 2.4GHz WiFi rather than Zigbee, which sounds like a downside until you remember it needs the bandwidth for zone data. In Home Assistant you can bring it in through the official Aqara integration or through HomeKit for fully local control. Every zone shows up as its own occupancy entity.
False triggers are the plague of cheap radar sensors, and this is where the FP2 earns its price. A ceiling fan or a curtain moving in the breeze will set off many budget units, while the FP2 mostly shrugs it off. Pet handling is also the best in this roundup. On AliExpress it regularly dips well under the price you see at western retailers, especially during sale events.