Honestly, it was a few months ago so I can't remember clearly, but I think he brought it back to an 8 or 10k, then to the 20k a few times until it got there.

I agree, I wouldn't even try to say the C12k compares to the Shapton and my skills definitely are not there yet as I can count on one hand how many times I've honed. I just find it very interesting that I can hone and finish on the 12k with my Hart no problem, but this TI just wont work with me.