Ceramic pit is heated mainly by radiation. There is less flow of air and in turn meat is more juicy.
In an UDS or Weber, heating is more convention than radiation. More flow of air simply makes meat drier. also the basket or fire grate design makes them draw much more excess fresh air, which makes the convention even stronger.
I know water pan idea.
But my fire basket can draw less air, and less convention, and makes meat less drier.