In recent years I’ve spent a week in each, late February in Palm Springs and early July in Provincetown. I loved both, but for vacations I would recommend PT first. Principally because nearly everything, bars, restaurants, galleries are concentrated in the same area and can be reached on foot. I stayed with friends in Palm Springs and they showed me the sights by car.
However if I had the choose which town to live in, I’d opt for Palm Springs because of the weather.