Marshall, I'd be curious to see how your rings are holding up with wallering out. Didn't you change a ring out a year or two ago that had cracked?
I still have my first set that I ran for 2 1/2 years as my spare set now, and you can definitely see the holes are worn funny.

I wonder if the CMC "plain faced" rings are made of the same material as StopTechs standard slotted ones.