Mine is not a heat pump.... I have gas heat and it is cheaper than a heat pump from what I understand... however, there are many articles that say the opposite....
I am a licensed home inspector.
Heat pumps are relatively efficient. I'd say on a scale of 1-10, if you put a high-efficiency gas furnace at 10 and a medium efficiency furnace at 6, the heat pump is about a 9. However, there are many other factors to consider:
1) Heat pump efficiency depends on the weather in your area. You see, a heat pump has an "auxiliary" heat system that automatically comes on and supplements heating when the temps get below a certain temp...usually around 35F. If you live in Minnesota, your auxiliary heat would be running all the time!
2) The auxiliary heat can be gas, but more often it is electric. Think of the electric auxiliary heat as a large hair dryer. It is costly to run these electric heaters. So if you live in a temperate climate such as Tennessee, Kentucky, etc....they are a reasonable alternative. Or if you live in any climate and have gas auxiliary heat, then not so much of an issue. I live in southern Indiana and I'd estimate 15% of the houses I inspect have heat pumps.
3) Heat pumps have an installation advantage...they do not require a flue unless you have gas auxiliary heat. There is no combustion...the heat operates on a refrigeration cycle.
4) Some people think heat pumps feel "drafty". The air coming out of the registers on the normal heat cycle is about 95F compared to 110F for a gas furnace. Some people don't like them for this reason. Since the heat pump has lower output temps, it has to run more...so they don't last as long. Typical lifespan is 10-15 years versus 15-25 for a gas furnace.
Hope that gives you some things to think about.