> Are they good options for cloud-freeish thermostats?

There are connected thermostats that do not feature a WiFi radio. I don't like zwave (I would really prefer WiFi with a HTTP or MQTT interface) but there is no thermostat that a) has a modern/working WiFi radio and b) a documented API.

Venstar is the only company that makes WiFi with an API but they seem to use the cheapest possible WiFi radios and I could never get mine to stay connected to my network for more than an hour or two. They also had a _really unusual_ firmware architecture: it was linux with a stripped down web browser; the UI was a SPA and it used some lua or js (don't recall, sorry) to communicate to the hardware driving GPIOs. They did expect firmware updates to be signed and that's where I stopped looking and moved on to a zwave thermostat.

I've got two of the Venstar Colortouch thermostats running locally with Home Assistant. They were spendy and their interface feels dated and clunky, but they've been totally reliable for me.

I'm working on https://sett.homes which is in this spirit. Instead of an Atmel it's an ESP32.

It uses MQTT with Wifi as you requested :)