80s/90s lore advised against ceramic balls, as these tended to develop microcracks with time.
Don't know how modern ceramics fare. I do have had, experimentally, a ceramic in a GyroDec for 3-4 years now (I think), but no time/inclination to follow up on its performance and wear. Nothing is obviously wrong, but then again, nothing got obviously better.
In a Michell-designed bearing (i.e. Syncro, Gyro, and later) the ball is sacrificial and meant to wear. It is good practice to re-orient it periodically in its housing, showing a fresh spot on its surface to the bearing cup and thrust plate.
Michell Orbe/SME IV/Lyra Delos/Michell Iso & Orca & Alecto Stereo/Quad ESL-63/Denon DVD-2930/Apogee MiniDAC/Pioneer N-50 streamer