Now that I am home and not typing from my phone, I will expand on my previous post.
What I mean in saying that a certain pipe may not work best for every single motor of a certain type, 10mm Cub in this example, is that not everyone uses the motor the same way.
Typically, Shearer or any other pipe builder is trying to sell you that their pipe makes the most peak horsepower.
In some uses, peak horsepower may not be the best way to go or best for that build. Maybe you need a broad curve or more bottom end opposed to peak horsepower.
Set up is key. Pipe choice should be decided on when you understand what you're going to be doing with the motor and how the pipe will affect that.