The ring worn in diff rings is THE PRIMARY reason a diff becomes inconsistent. The grooves get deeper, even if they are extremely smooth, and the diff operation is still very smooth. The effect is the diff is still smooth, but it takes more effort to get it turning in different directions, which makes the car less consistent in the corners.

This is DIFF STICTION, much like shock o-rings grabbing on a shaft. This condition is WORN OUT and needs to be serviced by replacing or resurfacing the rings--even if the operation is still smooth. When the rings wear grooves, even smooth ones, the ball is more affected by stiction because of the increased surface area the ball and ring contact each other with.

Here's the thing on ceramic vs carbide -- ceramic balls do NOT grip the rings like carbide. They just don't. That is a principal design quality of silicone nitrite ceramic balls. They provide far less friction. That's why they put them in ball bearings! In order to run the "tighter" and "very tight" settings that make this car great on many surfaces, you need some friction in there.

The bottom line is this: if you want to run a tight diff, you run carbide. Else you're going to be fighting trying to get the diff tight enough without seriously torquing the bejesus out of the spring and risking snapping a diff bolt, and then it will eventually slip. If you don't want to run tight diffs, ceramics last a very long time are a good option. KNOW YOUR OPTIONS.

I speak from years of experience on this exact carbide vs ceramic game. I've tried them all, many brands... some very exotic and mundane balls. My opinion from testing is this: Ceramics are fine on the REAR of 2wd and 4wd. Heck, I used to run them, I would run them again, but they are FAR too slippery for truck (T4/SC10) rear diffs and B44 front diffs.

Ceramics in the rear of my truck eventually made for a smooth diff that slips and no tightening it down will keep it from slipping, even so tight that it doesn't work right due to stiction.

Ceramics in the front of my 4wd resulted in a diff that, while it didn't slip, I simply could not get it tight enough in general. It took me a long time to figure out that it was the ceramic balls that did this to me. I was trying new springs, bolts, etc... went back to carbide, BAM, diff would stay tighter.

Rear of the 4wd or 2wd, either work fine. I don't run much tighter than standard in the rears of 2/4wd. Eventually the lube vanishes and they start to feel funny and squeak because they stay smooth so long, but that's a nice problem to have because it means you got a lot of good usage out of them before new rings and lube are needed.