My mom had a Corning smooth top. She loved it, I hated it. If there is a rim at all or indentation on the bottom of the pot it will not conduct heat. No cast iron....also, the smooth tops hold heat for a long time. Mom had to buy a whole set of Corning smooth bottom pans for the stove. You couldn't give me one of them. Also, the newer ones seem more prone to changing color and staying that way very quickly.