Bruce is as great fellow to do business with based on my experience.  Since
I elected not to have either done on my engine, I can't comment on their
value.  Perhaps if I had the rotors ceramic coated the coolant temps would
be higher and oil temps lower but, my oil temp was at 160-180F and my
coolant temps were at 200-210F, so I don't think ceramic coating would have
done me much good. My understanding is that it shields the rotors more than
any other component from the heat of combustion - so would probably help
keep oil temps cooler.

Ed and ALL,

  One advantage of ceramic coating on the rotary might be to keep the heat of combustion concentrated in the combustion chamber. The biggest problem the rotary has is excessive wall area for it's chamber size. While it may or may not help temps, I don't know, it should improve the overall efficiency.

Bill Jepson