Nest's two smart thermostats look similar, but they're very different under the hood—and only one of them is a "learning" thermostat. Read CR's expert review for the real-world differences. The Google ...

The budget-friendly Energy Star-certified Google Nest Thermostat is polished and pretty, but it isn’t a true smart thermostat, at least not like its older sibling, the Google Nest Learning Thermostat, ...