Flat bench is the best builder of the chest. Arnold had the best chest of all time, Sergio and Lou round out the top three imo. However you can tear your chest easily with this exercise as opposed to others. The reason why pros tear is because the tendons are not strong enough. Steroids make muscles strong not thier tendons, so they basically out grow them. Arnold and company were never on that much juice to make those concerns real. They were early powerl lifters who through time, grew massive chest and had the genetics to back it up. Pros now are dudes on the bench of a Div III Community College mens basketball team or former sprinters. Thier gains were quick and sudden. They can't flat bench and will never have superior chest.