Balls.....

In the 17 years I have run the Miller Carbon Teres turntable https://systems.audiogon.com/systems/8367 I have run stainless steel ball bearing on teflon coated brass thrust plate (original), stainless on delrin, silicon carbide on tungsten carbide, stainless on brass with delrin insert, brass on brass with delrin insert, and probably some other variations I’m forgetting. It is something to think about, when some giving advice have tried none while another has tried more than he can remember.

Bearings are actually kind of a complicated subject. It would seem the hardest smallest contact area will be the lowest friction quietest and best solution, but this is not the case. A tiny point of contact means high pressure means no lubrication even submerged in oil. Vibrations travel up and down the spindle. So the bearing material influences the sound more than just by contributing noise or silence.

Bottom line, you can only judge by listening. I would either just get the bearing and try it (paying some guy to do this, why? DIY!) or search around for listener impressions.

By that I mean only those who have heard this particular ceramic bearing on your exact table.

FYI the settling in described above is exactly as expected, the high pressure causes wear that stops once enough is worn to lubricate, and then it is settled in, wear slows to a crawl, and it sounds better. 

The design of the bearing should have input on your intended changes. Is the ball the wear point being the softer or a thrust plate meant to wear and wear at a reduced pace not an excellerated one. Something the designer thought of before the owner ignores it.
Why not just replace the ball with one of the same material but tighter tolerances....and better lubrication. Everytime you remove the ball to either replace it or reinstall the same one you introduce a new point of contact. 
So ,  just what are you so sure you are hearing....

Thanks melm. The TNT would appear to be an apples to apples comparison as I believe the bearings are quite similar. Wondering if the sapphire thrust plate is a sapphire watch face? Thanks m.c. I was hoping you would weigh in. Are you selling one of your turntables? There is one listed with the m.c. handle in the description. The gentleman in n.j. That is upgrading the bearings has an ad on that auction site. He also has a web page under vas but it does not list the bearing mods. 

That gentleman in N.J. has the same address as VPI! It must be VPI that does the bearing upgrade!

I replaced the stock ball bearing for a ceramic (Si3N4/Silicon Nitride) on my HW-19 MkIV using the stock thrust plate years ago. Made a significant difference by being more open/transparent, tighter bass. Just as important with that was the type of oil used and the amount. I ended up using 4 drops of Motul dbl ester/5w40/4T. This was after trying several types of oil/grease.