The Xiaomi are incredibly well made. They don't play nice with systems that are Zigbee compliant, so as @april.brandt is stating, let the buyer beware!
However, if you're already and Apple iOS user as I was, and have and Apple TV4, a HomePod or an always on iPad that can run the latest iOS, then there's a way to sync the Xiaomi devices to HE via Homebridge and HomeKit automations.
I didn't intend this when I bought the Aqara HomeKit Gateway, but it was inexpensive and they are solid and reliable when paired to their intended gateway. So once you sync them to virtual switches in HE, you have exactly what everyone has been trying to achieve all along - 100% reliability of very inexpensive, small (as you can now attest to) and well made sensors.
So for the most part, the Aqara HomeKit Gateway is handling my sensor input, HomeKit automations are linking them to HE via virtual switches, and HE is doing all the fancy automations around my home. Response time is instant. Cannot tell the difference between having the Xiaomi sensors paired to HE, vs syncing them to virtual switches via Homebridge.
