I finally got fed up with this device and disconnected it today.
It works OK as a standalone manually operated thermostat.
As soon as you try using it as a remotely controlled device the latencies defeat the purpose of it being "smart":
Android app is exceptionally sluggish, on a flagship Samsung device connected to the same WiFi network it takes at least 10 seconds to change your thermostat setting, sometimes it takes longer or breaks completely
If you wish to control it from a PC, you have to log in to the website which is also slow and will take you at least 15 seconds
IT DOES NOT have a local network integration with open sources smart home products like openHAB or Home Assistant rely on a slow cloud-based API
Every 2 months it looses WiFi connection, instead of retrying to reconnect you have to physically disconnect the device to fix the problem
It doesn't allow to control it remotely when the Internet is down
It works better as a health device as you will find yourself getting up and walking to it to change the setting rather than dealing with sluggish remote interfaces.