I don't have a pool because I still don't know if it would be a sensible investment. But I like it and if I were thinking about a pool, I would like a pool "in the country". Somehow it fits better in my gardens. But it is definitely more expensive and, in the event of an accident, a much more complicated repair. Above the ground you throw, throw away and fertig. Dismantling the pool in the ground means re-drilling the entire garden. And or ???? include clay and that's it. And as for the water temperature, the overall construction of the pool and its technical equipment is probably more decisive than whether it is below or above ground.