To follow up on the SEER thing, I wanted to know what HSPF rating was all about. So, what does HSPF mean anyway?

It is basically the same as SEER. It takes into account the variations in temperature that can occur within a season and is the average number of BTU of heat delivered for every watt-hour of electricity used by the heat pump over a heating season.So a HSPF of 10 delivers 10 BTU/hour of heat per watt of electricity.

The higher the the HSPF number, the better. Most units have at least a HSPF of 9 but some can go beyond 12.

Rebates and incentives are the same for Heat Pump as they are for Air Conditioners.
One federal, one State and one local. They can be found for your location by looking here. (At least in the USA) Federal is worth up to $1500, State $100, and Local is $200. I need to purchase at least a SEER 15 and HSPF 8.5 unit.

Now, I like Heat Pumps. They don’t burn things. (I don’t like Gas in the house but currently do have it.) They can be very efficient. And are very easy to maintain. Plus since it is a heater and air conditioner all in one, one less appliance to worry about.