In the last few years golf equipment manufacturers have had to up their game in order to convince us golfers that we should upgrade from our current model. Each manufacturer is taking a slightly different route, but certainly a big focus nowadays is aerodynamics. The name of the game is reduce airflow in order to help you eek out as much distance as you can.
The engineers at Callaway went to the foremost expert on aerodynamics and partnered with them to make the XR16. They went to Boeing. In the airline industry the focus for the past few years has been remarkably similar to what has gone on in golf club design. They want to make planes lighter and they use materials like Carbon Fiber in order to accomplish this. They always want to reduce drag as much as possible to save on fuel costs as well.