No matter which cam system you have on your bow, it must be tuned or rotated to factory spec for the system to operate the way it was designed. Modern string materials are very good but sooner or later, which ever system you are shooting will need maintence to keep performing the way it was designed. I don't think the statement that single cams are faster with heavy arrows that duals can be proven until a bow is built that can be set up with a single cam and dual cams with the exact same force draw curve, draw length, brace height, axle to axle length and have the same amount of inherent friction in the system. Marketing is the largest driving force to get people to buy new bows. New systems, colors, weights, performances and promises, etc is what keeps selling bows. Thay are all good otherwise they wouldn't be selling.