Had the Hive. Useful for turning the hot water on when I was at the gym and wanted a bath/shower when I got home. Also had it set with the proximity of my phone to the house to turn on the heating (obviously only if it is colder than the thermostat setting). Great pieces of kit. The Nest has more connectivity to other devices (Alexa, cameras, smoke and CO detectors etc) and links them together (i.e. Turn on a light in the house when the outside camera detects movement at an odd time or turns off boiler when it detects CO), so is the one to go for if you are looking at a few things.