Depends on speed for me, if I'm around town or at slower speeds I'll tend to drop the windows (and get my elbow out). Then raise them when I get out of town and the speed increases. Cuts down on the wind buffeting with them up.
Same as Caius…. Down when driving between 20-40mph. Then up for anything faster. I do have the side covers for when the roof is down but I’m yet to fit them to see if there’s much of a difference in wind noise. I’ve trial fitted them and they do look good!
When it’s cold ie around 5c windows up, car heater on and seat heaters on. When it’s hot above 20c at up to 50 mph, windows down, above this, windows half way as it quietens down the tyre noise but makes the exhaust sound louder.
almost always windows up - because its either too hot or too cold most times and I have the aircon on which works better with windows up. Plus I have a killer tint
Halfway up at slow speed and warm temperatures, all the way up at higher speed, windy of cold weather. On really hot summer days all the way down plus wind deflector off.