When I was renting I had the aircon set at 25 in summer & 20 in winter & would only run it on days were it was really hot or really cold as I'm a big believer in putting on a jumper in winter before turning on heating. When working in an office set at 22 I would freeze if I wasn't wearing 2 cardigans!
But now I don't have aircon & my west facing kitchen with the exterior blind down is a lovely temperature right now, I can highly recommend them as a way of keeping rooms with large glass windows cool.
Something I don't like about aircon running all the time is the noise, I can hear a unit 2 houses away every night even though my windows are closed