In the new F3D engines like the world champion MB 40 we use ceramic bearings with big success. In our experience the last longer and they dont chance the play in the bearing while the engine became hot. We use normaly WIB from Swizerland in C4 now we use ceramic balls in the bearings.
It is also very helpfull to use only one ball in ceramic because this singel ball maks the bearing very clean and polished the bearing inside.
In Germany the ceramic bearings are not such expensive than in USA. Mostly we buy only the balls and chanched them ourself.
Ceramic bearings last 10 times longer than steel onces under very hard conditions.

Best regards M. Jakob