Bob, I agree with Lynette, especially for the non-full-timer. When you use your rig often, but not for durations that allow you to rent sites monthly, you are then renting (usually) nightly. Electricity is almost always part of a nightly rate. As such, the heat-pump makes great sense. And the way the heat is dispersed throughout the RV makes more sense to me that running 2 space heaters.
In any event, it's just another choice of heating method for some to contemplate.
Jim