I got one of these for Christmas 2017, and installed it the following day. I have a smart home and mainly got it because I like to automate everything. I was surprised by how much of a difference this thing made. I just installed my second one last week on our top floor. Our house is 3 stories and nearly 6K sqft - additionally, it is propane powered heat, so it can get expensive if not managed properly.First off, the installation can be tricky because nobody wires HVAC systems in a uniform fashion. I did it wrong both times but I called support and 5 minutes later, they were both working perfectly. Send them a few pictures and they tell you how to change up your wiring. The app is great and makes it easy to set your schedules and modes. I have them both integrated via smartthings and alexa, so changing settings is super simple even from the comfort of your easy chair.I decided to get a second one after I reordered propane last month. I expected 1300 gallons, and only needed 1000, so I saved 300 gallons of propane over the same period of the previous year. Propane goes for between $2-$3/gallon, so these things will pay for themselves in months if you set them up properly around your schedule - I saved ~$750 from December 2017-September 2018. The 3 lite has everything I need. Love the subtle refined looks unlike Nest which screams "look at the smart thermostat!"Anyway, house is comfy when you walk in the door at night, vacation modes are handy and integrates with smart hubs and Alexa to complete my geek thing. I'll be ordering a 3rd when I add a zone for the basement in the spring.