The ceramic balls i use are the TZ type.
They are slightly less in weight compared to metal balls, so ball physics is a little different.
They stay clean . I only have white rubbers on my gottliebs. Not sure if black rubbers would leave marks ??
But the ones SWINKS was posting about  have got me interested. The weight would be closer to a normal metal ball. But still with metal ball attributes. ie magnetics and weight.