I've been using the Google Nest Learning Thermostat for about 3 months now, and it's completely changed how I interact with my home's climate. The polished obsidian finish looks like a piece of modern art on my wall - way sexier than my old rectangular thermostat.
The installation was shockingly easy considering I'm not particularly handy. The compatibility checker told me exactly what I needed to know before purchasing, and true to their word, it works perfectly without a C-wire. The included temperature sensor in my bedroom means I no longer wake up sweating while the living room stays chilly.
What really surprised me was how quickly it learned my patterns. After about a week, it started adjusting temperatures before I even realized I wanted changes. The 'Farsight' display is brilliant - when I walk into the room at night, it subtly shows the temp like a bedside clock before dimming down.
The energy savings are real too. My last electric bill was 13% lower than the same period last year, and that's with more extreme temperatures outside. The app makes it easy to override the schedule when needed, though honestly I rarely have to anymore - it just gets me.