It is a highly debated topic. Some people get away with spraying the gasket, but I have experienced bad things with friends cars who have used both a copper gasket and/or spray along with the MLS with spray. I have read online somewhere about copper not mating well with the aluminum in our cylinder heads, be it either a gasket or in the form of a spray. I'll try to find that article, I believe it was written by a tech from an aftermarket gasket company.