The main reason I'd be hesitant to get one is because I don't really ever set my thermostat to heat. Even during the once-in-a-lifetime freeze a few years ago, we never ran any heaters (granted, we live in an apartment, so only like 2.5 walls are exposed to the outside - would be very different in an actual house, but I'd still rather opt for better insulation, a single space heater, and a heated blanket over spending that same money on a heat pump that does nothing for years at a time).