For those who believe in the idea of the doufeu, it seems that the temperature gradient is better using it stove top with heat from the bottom. This supposedly improves the basting. Cooks Illustrated did an article about it. I have one and use it as a Dutch oven, but I don't use the ice.

Thanks for your help Wekick. That was the impression that I was getting which is why I hesitated buying it. Now I know for sure.