Hrm. You probably know better than me, but I always assumed that since my cooling cost in Summer is 5x the cost of my heating cost in winter (with similar differentials, eg. heat+30 degrees, cool-30 degrees) that it was a less efficient process.

The napkin math still doesn't make since if I have to increase the cooling of house ~half the day (would be more since summer has longer days.) Other considerations would be extra wear on the HVAC equipment and just the comfort impact of increased fluctuations.