[zdragnar]

US single family homes are, by a large margin, primarily heated via the central air system (the same ductwork that supplies cold air in summer).

My experience with both is that I prefer central air heat. That said, they will perform worse in a drafty house- air is a very poor carrier and storage medium for heat compared to water, so if you have a room with a draft away from your thermostat, it'll get colder faster; a radiator in the room would essentially act as a heat bank.