Yeah Iris was the one I was considering for zigbee too. I haven’t found a better alternative but would be willing to pay a bit extra if there is a “premium” alternative available. How has the battery life been for you? The support page says up to 2 years, and it uses the larger CR-2 battery so I assume that is somewhat accurate:
It doesn’t have many reviews though so hard to say how good it is. They rate their battery at 5 years but that seems like an overestimate based on the fact that it uses a tiny battery, or maybe it just has a very slow response time.