Excellent thermostat with great app and looks beautiful too! Easy install, neat appearance. It controls our heat pump and seamlessly switches over to the gas furnace when the outside temp drops too low. App works perfectly with remote control so we can in down if we're out or away and turn it up just before we get back. We're using it with one sensor but might add more. Haven't tried geo-fencing yet but very interested to see how well that works. The app is also able to control our Honeywell thermostat at another location.
Love that the app looks and behaves just like the thermostat on the wall, with clever subtle/elegant color coding showing at a glance whether its heating or not. Love it! It also helped that we got an energy rebate from PSE (Seattle)
I did a lot of research of the brand names of smart thermostats. I own other products of these other brand names and after all that I chose the T9. I have had it for over a month now and am more than satisfied with the quality and functions. My advice to anyone considering a smart thermostat is to do your homework on what you want and need. If the T9 meets your needs I am confident you will not be sorry. It is cheaper than the brand names but it lacks nothing in performance.
The thermostat was easy to set up and to add additional sensors. It connected to Wi-Fi easily and the app performs as expected. So far, the system seems to be very stable and reliable with the five additional sensors.