dont know the difference between the wrc and cometic one but i have seriously abused 2 cometic ones with no problems. at one point even letting the car idle past warm up temp for ages without any water in the system wondering why it was SO hot ) other times on track when it over heated etc. the general concensus appears to be that they are great but you must have flat head/ flat block and my take on this is that people who go the cost saving route (cometic) may also skimp on getting the head skimmed whereas those who have paid the wrc cost would have had that done too given the cost of the gasket.