We replaced our air conditioner a couple of years ago. Our old one ran on the old refrigerant. Kept it set at 78 all summer long and was comfy. Our new air conditioner is set on 76 or it feels hot in here. Hubby likes it on 75...which I change all the time. lol We had new energy efficient windows put in too so I think it’s the new refrigerant. It just doesn’t work as well.
I run my AC on 68
I’m in the South
Man 75 would be stuffy
I realize thermostats vary though
I have central ....3 units
But I run a small 200 dollar window unit in my bedroom
I like the hum and it gives the central unit a break
During day I put it on economy and at night it’s on full bore
Three summers now
In Nashville late April maybe till October