I’m a home automation and “green freak”. When I built my home, I provided the light switches that I could control with my home automation software. A home that does what you want automatically is fun and convenient. I have three nests and the story is the same. In the Winter, I let the house cool down at bedtime and warm back up before it’s time to get up. Leave the house for work or vacation? It knows and adjusts the temp for you to save money. Plus you can tell it when you are on your way home so it is comfy upon your arrival. Now combine both with an Amazon Echo or . . 8 and really enjoy home control via voice command. Adjust several devices like lights, whole home audio and more with a single command like “Alexa, dinner time.”
Does Nest save money over its lifetime? It probably depends on how much you are away from home.
David
"Help, help, I'm being repressed!"