When we're not home, it's off. A programmable thermostat would just allow us to turn it back on before we get home, which would cost more. The good thing about turning it on when we get home is that it feels good to sit in front of the vent.
When we are home, our deal is to leave it as hot as he can stand it in the summer (75, night and day) and as cold as I can stand it in the winter. Now that I'm home all day, I turn it on for him at around 3:00. It's been about 83 at that time--and I start to lose energy and stop doing things, so that's probably where I'd set it) and it's still 81 when he gets home.
We have a ceiling fan over the bed. And he strips down to a t-shirt and undies. (Common quote when he gets home: "I'm wearing too many pants.") While I'm generally wearing shoes and socks and sometimes a sweater once it gets down into the 70s. (I'm better at dealing with heat than cold, which is why I live in the south.) Our concrete hallway feels really good on bare feet in the summer. He also likes to refrigerate a wet bandana and tie it around his head.
It seems to take a very long time to cool off when we turn on the A/C. Last time I replaced the A/C, I got one quote from the same guys I used to weatherize my house and another quote from highly regarded folks who actually do the calculation to give you just the right size of A/C (too big and it switches on and off too much). Well, the former were going to replace the old one with one of the same size (2 tons), which I thought was too small, but the latter were going to give us an even smaller one. For more money. We went with the former. Our next plan is to put a window A/C in the bedroom and turn off the central A/C at night. (Opening the windows or using the attic fan doesn't really work when the temperature doesn't drop below 80 for long or at all.)
