Save your money.... ceramics have their place but for the most part wont help in our application.
I have been down the ceramic path in RC and some other applications.
Ceramics are a must in a nitro RC car clutch for example because they can withstand greater heat than a steel bearing with little lubrication. They also excel as a front bearing in a RC nitro engine because not much fuel air mixture gets to the front bearing.
They dont seem to hold up as good as wheel bearings and dont seem as good in a semi dirty application or one that has shock loads. While the balls are very hard they also break or chip easily.
The cheaper grades (yes there are many grades of ceramic bearings) are really just a ceramic coat over some substance that turns to a powder when hit with a hammer...lol
I also tested... the best I could.... the common belief that the ceramic bearing has less resistance... spin better... but I couldnt find any proof.
If you must go ceraminc stay away from the cheap chinese imports and work with a reputable company... I have used BOCA Bearing in the past with success.
I believe they have some good reading on ceramics on their website