heat pump opinions

ok, so we will be replacing the furnace in the new house, as it's older than I and is tremendously expensive to operate. I quite literally watched it eat about 14 Cu Ft. of gas a minute while operating.
A friend recommended a heat pump install as well, currently the house has a central air unit that is in working order, I'm considerig it, but with a highly efficient furnace I don't think it would be worth replacing the current air conditioning unit. His experience was based on a house that had electric heating and he did see a significant decrease in the monthly heating bills, but I just doubt that it would be worth the money, especially considering that it already has A/C. So what's the opinionf from the HVAC gurus?
Bear in mind that this will be in northern Ohio, with week long stretches of temps below freezing. I realize that as the temperature goes down the delta for efficiency goes down also, which is what really makes me question the logic and expense of installing such a unit.

 

To use a heat pump, in the real sense, you need to drill a well 20 or more feet down, and use the Earths warmth to heat or cool, by pumping water down and back up……….most units use the outside air, to do the same thing………since there are all ready air duct’s in place for the a/c, there are add on heating units

 

A heat pumps works only within a certain temerature range, below which you need an additional heating source - sometimes electric.

You'd be amazed at the effeciency improvements made to conventional furnaces. Oil or gas, you'd see a noticable difference in the quality of heat and your utility bill.

 

this would be an air to air unit, as there's no place on the property to do a proper ground unit. My major concerns is that during times of freezing temps, when the heat pump would be most useful, the air units suffer from poor efficiency and icing on the coils. oh well, I suppose we'll just go with a regular furnace, it's something that can be added when the traditional A/C unit dies.