Just to add my three cents....... Our '84 Spider has heat and ac. Here in SE Florida, I've never used the heat, although it works perfectly. But, we do need the ac, even in the winter. We rarely use the car due to the low mileage, especially in the summer. On the occasion we want to use it for a nice drive and dinner out, the ac comes in handy on the way there. And then, even in the summer, well put the top down for a nice cruise up the Intracoastal or beach roads for the ride home. And take the long way, of course. Same in winter also.
As for the ac unit, ours kicks ***!! Works perfect to the point of having to turn it down to 2 or 1 due to how cold it gets. Maybe as the mileage goes up, and it useage goes up, it might change. But we love it. One of the reasons we bought it. Sorry to digress......
1984 Spider Veloce Deluxe
1969 GT 1300 JR
1969 1750 Spica Spider Veloce
1952 MG TD