These are the two biggest complaints about heat pumps: one, they blow out air that is only marginally hotter than the room air (unlike a furnace, which pumps out hot air, or a scalding radiator), and two: heat pumps take a very long time to warm up a cold space. If you try to ramp up rapidly, you’ll often trigger the “emergency heat” which is usually electric strip heat and thus VERY inefficient and expensive.
Heat pumps work best when you maintain a room at a stable, comfortable temperature.
You don't want to use a heat pump to blow hot air. You want to use a heat pump for low temperature underfloor heating. The heat is right where you want it, the heat pump doesn't have to work as hard (because of the lower temperature). And everyone is happy.
"Heat pumps work best when you maintain a room at a stable, comfortable temperature."
Right, but for this to be economical, you need to have a well-insulated house, which is pretty much impossible to retrofit. So practically speaking, only newly build houses (and then, only those to the highest energy standards) should use heat pumps for heating. If we go around promoting them for other purposes, they will build up a reputation for being a crappy solution and people will shy away from them. That's my main problem with people promoting them - they often promote them for retrofits.
Heat pumps work best when you maintain a room at a stable, comfortable temperature.