Irene, Ithink that what Mike is trying to say is that a aircon unit(heat pump) costs only a quarter as much to run as a fan heater,econo heater whatever as its much more efficient.
I think- he will probable correct me later but that's my take on the subject!!!
I don't really think that's a big plus unless you are there for lenthy periods and obviously you may well run them summer and winter which would make them expensive.
That said I don't like to be too hot or cold. I have a very narrow tolerance for temperature! (probable between 65-75degrees F) so Mike tends to indulge me!
Gloria