Hi all. I have about 50 switches/dimmer and 10 outlets and lots of contact sensors now. I’m ready to add motion sensors but they need to be Zigbee. I did a community search and most of the threads are a couple years old. Anyone have any recommendations on fast responsive motions that don’t drop off the mesh? (Xiaomi).
Thanks!
If you can find Iris V2 or V3 (not V1) on Ebay, they seem to work well for everyone, myself included. I also really like the Hue sensors and the 2 AAA batteries literally last for years. The Hue also have light sensing and a configureable re-trigger time down to 10 seconds on the motion sensor.
I've gradually moved from Xiaomi/Aqara to Sonoff sensors.
I have not had any issues with the Sonoff devices. They stay connected whereas my Xiaomi/Aqara would drop off every so often.
My experience is they react slightly slower than the Xiaomi/Aqara devices but not by much. Certainly quicker than my Fibaro and Neo z-wave motion sensors.
The price point is around £9 to £10 in the UK.
I’ve been reading lots of good things about the Hue sensors. I assume they are Zigbee 3.0? The AAA battery is also a huge plus. What batteries does the Sonoff sensor have? Also is there a native driver for it in HE or do you need to find a community supported driver?
Plenty of good z-wave motion sensors out there too. You don't have to limit yourself!
I actually do. The areas I want motion sensors are way too spread out and far away from the hub and 98% of the devices I have are Zigbee. The few zwave devices I have are endpoints only. So to avoid communications issues, that is why I am staying with Zigbee. 
CR2450. With the Xiaomi devices the batteries last up to 2 years. (That's how long I have been using them).
I'm using a community driver that works extremely well.
They are quite small as well. Half the size of a Hue.
I've had nothing but headaches with Xiaomi devices. Finally threw away the last of them last week.
Everyones mesh and setup is different though.
I'm a fan of the Iris sensors. They're stable, report temp and humidity, and take a CR123a battery that lasts forever.
I've bought a bunch from this seller.
Great feedback guys thanks. I am going to look at the Hue and Iris sensors for places where I woul d like a multisensor in place, and will use the Sonoff for the spots that a low cost simple solution is just fine. 
Wait, the thread title is “Best Zigbee Motion Sensors”. While the ones you’ve listed here are indeed Zigbee motion sensors, the title of “Best” goes to the NYCE Zigbee motion sensors. 
I don't think they are the best based on these reviews! 
https://www.amazon.com/NYCE-NCZ-3041-HA-ZigBee-Motion-Sensor/dp/B00W4C8JAK
As always, take reviews with a grain of salt. There are 11 reviews. These sensors work well with Hubitat, in spite of the 2 reviews saying they don't. They're discrete. And they have a nice ceiling one. The only downside is that they are expensive.
Mike still have several Zigbee motion sensors available here for $5 (ST/PEQ Centralite) or $7 (ST) each. They may not be best, but they are very good. IMHO for the price, that makes them better than best.
(*) e.g,. my biggest complaint with the ST motion sensor is the use of a CR2450 battery
Amazon reviews can be trusted about as much as Ted Cruz about as can.
Politics? Perhaps a Biden reference is in order.
I purchased a few Philips Hue at Home Depot two weeks ago and I couldn't be happier. I love the magnetic mount, the AAA batteries and the lux reporting for spot motion lightning.
They are very fast (compared to my previous aeotec) and fully supported by Hubitat.
Keep politics out of here guys. Let's keep this on topic. 
I like them too. It reports temperature as well, which is useful. I like that you can set them on a shelf.
No politics. Just pointing out you don't have to be a proctologist to spot the obvious.
Big fan of the Philips Hue indoor and outdoor Zigbee motion sensors. Pair beautifully directly to HE and report motion events quick for light automations. Indoor I use them in all the major walk-in closets, laundry room, and kitchen pantry to automate lights when walking into those areas. Outdoor I use them for automating security lights at night and also for outdoor temp sensors.