No ceramics. The AE diffs work GREAT bone stock. I can definitely tell when they're in need of maintenance though.

The diff on my 2WD lasts a good while, but the grease degrades pretty quickly. If I'm rushing, or just being lazy, I'll just pull the thrust and clean that.

I run my 4WD hard (boosted 6.5), so the diffs don't last nearly as long as the 2WD, but I can't complain with the way I drive the thing. Just take your time breaking them in when rebuilt, and set your slipper carefully.