It can be amazing how much a difference insulation and an efficient HVAC system can make.
My thermostat is downstairs, just off a large room with vaulted ceilings. Since the hot air would float up to the ceiling, in the winter the furnace has to work harder to keep air around the thermostat at the set temperature. And since there are two air registers in the master bedroom upstairs, trying to keep the downstairs warm made the upstairs stifling. So I settled for setting the thermostat to 67-68, and it would be slight cool downstairs and not overly warm upstairs.
Last year I had a local contracting company specializing in energy saving home improvements do a home energy audit. Turns out the ductwork serving downstairs was leaky, so the furnace was cranking out extra hot air trying to keep the downstairs warm. So I had them fix that, as well insulate, and as seal all the leaks from the attic and the crawlspace into the house. Now the upstairs is the same temperature as the downstairs (I've taken a indoor/outdoor thermometer around to check), and I'm going to have to bump up the thermostat setting up a few degrees to be comfortable. However that will still use less energy than before, and I got a rebate back from the natural gas company for doing the work. And even though it doesn't get that warm here in the summer, the upstairs rooms stayed cooler in the warm weather too (less heat radiating down from the attic.)