A lot of people also don't understand that a heat pump is still heating your home, even though the air it blows might be a bit lower than your body temperature, so it feels "cool." When that happens people assume it has stopped working and switch to aux heat. This is one of the major reasons people insist that heat pumps don't work in the cold, even though they still have plenty of capacity margin to heat the dwelling.

My old system was actually set up so that it would pulse the electric aux heater every few minutes or so to help prevent this "drafty" feeling, and to extend the time between defrost cycles.