Upon unpacking, it looks like the luxury of an Apple product! Mechanically and aesthetically, it is superb. Installation: better to be a little responsible for what to connect and where (on a bathroom Acova with pilot wire, I had to add a diode because Acova command is a bit special). The screen is readable parfaitemen, very friendly programming including to connect to wi-fi, on the thermostat itself. If you create an account on the Nest site then you can do anything from a computer or a smartphone, the site Nest and iPhone app are simply perfect. The regulation is half a degree, it measures every day the heating-up time; thus, it can be anticipated to be at the right temperature at the hour! There's even a mode locked 'which leaves the user free to change the temperature within limits we give, without being able to modify the remaining parameters. In short, an expensive product in absolute terms but what quality!