I have been watching all of the reports, but have not used graphite, and probably will not.
There are also reports of particulate accumulating on the Cast Iron (cathode).
A lot of the comparisons I am seeing, are relative to what anode material an individual has used in the past... most have been small, insufficient sized anodes, of regular steel, etc.
So using the Graphite has shown them an increased efficiency, etc. Some/much of that is due to finally having an appropriately sized anode and improved conduction.
I still think a lot of folks are not running enough AMPS to really measure results effectively.
My questions to be answered about graphite will be the measured absolute life of the plates. How many pieces cleaned, at # of Amps.
I have used Stainless Steel from very early on, and have a good supply <finally> and more on the way, so I do not feel that my current electros can be improved upon.
Long lasting and efficient,
and I run mean-clean electros.
LYE BATH First,
then electrolysis,
goes a LONG way to more efficient conduction, and less maintenance.