Easy to install and great to use! I had an unsuccessful experience with another brand, and then chose the T9 and am delighted. LOVE the functionality of it; and, really appreciated the additional room monitor to independently confirm temps!
Thermostat works well and is aesthetically pleasing. The phone app is a little cumbersome with options and settings located in unintuitive places which takes getting used to.
Set up required an HVAC technician because of the C wire requirements. Modifications needed to be made to the circuit board of my HVAC system. The thermostat works well once installed and set up. It does not seem to allow two phones to control the system, so I must rely on my wife to program the days and so forth. The thermostat does save us on our electric bill through a program with our provider.