St Barth was 26-28c and a 10-20kph breeze, most homes do not have air conditioning in the main area. We only used it in the bedrooms. Most restaurants also do not have air conditioning and are open air.

Even in hot places driving open in the morning or at night is a joy. That's why many cars are convertible in Miami. Of course if you wear a suit at noon you won't open the top... Still buying a couple doesn't make much sense when you can buy a convertible version. Now cars are designed from the ground up to be convertible and the performance difference is small to even worry about it. Car get heavier but top mechanism get lighter, reducing the delta. Also torsionally has greatly improved in open cars, and I won't even get into carbon tub car designs. More importantly maybe, driving a convertible even with the top closed gives you the impression that your ride is special and adds to the ownership experience. There is one downside: they are more pricey... But you might get some of the price difference in resale.