I went with Ecobees mainly because they offer the easy export of your data and have an open API to interop with.

I originally planned to use my HomeAssistant install to orchestrate it a little with the Awair products I have, for example, turn the AC fan on if the co2 starts getting high to flush the air, but a while ago the Ecobee app can pair up with Awair itself, so I've had no need.