Hello all, I've noticed that a lot of other motion sensor posts are out of date. Shall we start a new one for 2022?
I've also noticed that priced have gone up significantly.
What are people buying these days?
I've recently played around with the Sonoff sensors. Very inexpensive, but unreliable.
Thoughts?
I'm using ThirdReality motion sensors now.
$20 each and powered by a pair of AAA batteries.
Have you seen this thread?
I know it's at risk of being "outdated" by now, but with only a few months left in the year, maybe they'll do another one soon. 
The community favorite there, the Iris v2 (and v3, I guess...) sensors, are long discontinued--and were then, too--but I guess that goes to show how much people liked them. I'm a fan of the CentraLite Micro motion sensor as a similar replacement, and it got a few votes there. They are about the same price Iris sensors were when they were at their lowest new price, $30 USD, though Ezlo (their new owner) often has sales, maybe more around the fall and winter holidays in the US.
I'm sure the SmartThings Motion Sensor, now sold by Aeotec, is as good as it was before, but for $40, I'm not about to find out. (Still reasonable by Aeotec prices, though!) Hue is also great, but again, more expensive than some others.
For cheaper options, I've tried Sonoff but also wasn't impressed. I do like the ThirdReality sensors mentioned above, and they're also pretty inexpensive. They just don't look quite as nice, and I haven't had them long enough to comment on reliability. They are just motion only, but the "extra" features like temperature in a motion sensor aren't always a concern for everyone.
Looks like you're in Canada, though, so what you can get--and how much it costs--is likely different than the US. These are just a few things I'd look at if I had to by more motion sensors today.
Check out the amazing work being done by Krassimir Kossev with Tuya devices.
Not officially supported by Hubitat. As far as the PIR sensors are concerned they are very reliable and fast. The only thing about the small round one is the brightness of the motion LED. Small irritant. The radar devices you will have to read the users comments.
I'm using the Aqara FP1 sensor.
It is fantastic. Works great and is very stable but requires a lot of patience and possibly several attempts to join.
This is so application dependent. Writing a white paper on the topic is on my to-do list, albeit a few pages down.
Sonoff - great for sprinkling around where the application is not very challenging. They are my go-to for closet ceilings. One is at the top of the basement stairs. The coin cell battery is a downside, though I have been getting over a year out of the original batteries. Oh, and they are as ugly as sin.
Hue - my favorite for outdoor (all 4 corners). Indoor ones are fine, but I don't have a great use case. Right now, I have these in our attic, mudroom, and garage. Common batteries and long life.
Bosch ISW-ZDL1-WP11G - the best for wide areas and pet tolerance. Uses something like 6 x AA batteries, so size is the obvious downfall. If you want inconspicuous, then this is not for you.
Availability is now sparse or expensive. These are in my "great room" (detects kitchen, dining room, and living room), my main hallway, my wife's office, in-law kitchen and our sunroom.
Visonic MP-840 K9 - my replacement for the Bosch. Smaller, but response is a step or two slower. Availability at good prices on eBay. CR-123A battery is presumably good for 5 years. These are in our in-law den and the bottom of the basement stairs.
3rd Reality - I have one on the shelf to test. I like the form factor and the asymmetrical detection zone (alter the vertical range by turning it upside down). As noted, common batteries. I could see these replacing Sonoff applications.
My absolute favorite indoor sensor is a hardwired Lutron MS-OPS5. If your switch location is roughly where you want to sense motion AND you just want it to trigger lights, then don't over-complicate matters. This is robust and fool-resistant. I have these in laundry and utility spaces.
My absolute favorite outdoor sensor is a hardwired RAB Stealth 360. Similar to above; it just works. It is a relay output, so you could feasibly use it along with a smart relay like Zen51. Over the garage right now and planning another at the back steps.
Unfortunately, I can't seem to access the aliexpress store. Bizarre.
So far so good. Easy to pair, seems to report very quickly (as expected from Zigbee)
In Canada, I'm not sure there is a cheaper option.
The unit itself is a little big, but honestly, again, for $22, I think expectations need to be kept low.
I'll wait a while to see if it gets dropped. My Sonoff for some reason got dropped off Habitat. Going to have to re-pair it, but we all know the nightmare that causes.
The third reality are great. The form factor with aaa batteries is a plus for me.
Third Reality form factor is unfortunately not a WAF winner for me. Showed my wife one of them and played up the battery life improvements and she just said "Big and ugly."
I wasn't sure if she was referring to me or the sensor. Maybe both? 
Regardless, the sensor was a "No" for me, unfortunately. 
The ikea motion sensor is cheaper, but currently not directly supported by Hubitat.
Not sure if that will change with Hubitat's Matter solution in the future.
You can use Home Assistant and the Home Assistant device bridge to get them into Hubitat though.
We need to start a wife support group!! 
Meetings every Monday at 5 pm to discuss the "ugly weekend."
Ahh...but the Iris v2, that is the piece de resistance. Teeny-tiny easy to hide, fast, long battery life. Why they could not just keep making it I'll never understand.
If you have a dog and want sensor immunity the ecolink 2.5 zwave plus is still good. long battery life but slow response time. I think about 3 minutes before it resets.
Actually 4 minutes per the manual. I have a couple and they are rock solid, but because of the slow response time, I can only use them in low traffic areas like walk-in closets. The 2 of them are about 2 years old and the batteries still report 100%.
I have an Aeotech multi-sensor, that was expensive, but looked great with the recessor. Unfortunately, it was way to slow to use where I wanted. I use it in the garage now, which is a bit of a shame, but it's powered on a usb, so it's very reliable, JUST SLOW!!
For me the EcoLink sensors have worked great until they don't. I use the outdoors for my security lighting. The neighborhood cats don't set them off. In the case of security lighting I'm happy with the four minute cool down.
I've had some that worked for a while then dropped off the mesh. This is likely due to poor mesh connectivity with the impacted units. I've found them tricky to get back online. Another got blown down in some sever wind and I ran over it with my Jeep so I can't really fault the sensor. I set it aside and some crackhead noticed it and scurried off with it. I don't know what he was planning on doing with some crushed electronics.
Most of the time they work great. I've improved my mesh and need to replace a couple of damaged sensors. They remain high on my recommendation list.
I'm going to try a couple of the Thirdreality sensors.
I picked up 30 of them when they were selling on ebay new for less that $5. I love the coverage with 2 or 3 in each room.
You were a lucky man that day. 
I bought some extras from someone a few months ago as backups, and will sometimes open up the box I keep them in just to look at them.
Download the Hubitat app
