Now I understand what you meant. I agree with you on the downsides, especially when it comes to noise. And I believe it doesn't only apply to full throttle flight. To fly at a certain speed, a 15x4 needs higher rpm than a 15x8, so I believe that it produced more noise all the time, not only when running at full throttle. In my experience, a medium pitch prop sounds softer than a low pitch prop when flying at "medium cruise speed", do you agree?