I've waited to weight into this discussion. .. In my heart, top down, windows down all the time down to 35 degrees. Bundle up when its cold, and enjoy what nature has to throw at you, laugh in the face of adversity..
But I'm getting old. My comfort is becoming more and more important. In the summer top down always, windows down around town, short trips down the freeway, the same. But for a long drive on the freeway, it's windows up. I have a wind blocker installed so the cockpit is relatively calm, and I don't get windblown, so I don't get tired either. When daylight savings time changes, on or off goes the hard top. On a long trip, as Rick says, top up is the only way to survive. Three or four days baking in the seat is killer, and the top is worth 10% in either fuel economy or top speed.
On really hot days, when you see the luxury cars with their tops up, they have the AC running. I get that. But on the medium days, if you're going to buy a convertible, USE IT. After all, modern cars have electric tops. How hard is it to hit the button?