Neither are paints, or any other breed.
But, a lot of people do breed Appaloosa's for disposition. All the appaloosas I have rode, have had good temperaments, and no buck, rear, nonsense stuff. Though we all slip every now and then. And, they had all been trained very well, handled as babies. I know their are crazies out there! But, from my expirence with good horse people and their appys' they have all been that well behaved. =]