3D requires responsive midrange. It's not the attitude or the fact that it's being thrown around.
Most sport or pattern is near full throttle most of the time where the engine is just tuned for max power.

Download this video of McDDD flying a Primo with a 55AX. Listen to the throttling.
[link=http://www.smilexpress.net/photos/RC/ProBroVideo/2009_mcddd_no_music.wmv]http://www.smilexpress.net/photos/RC/ProBroVideo/2009_mcddd_no_music.wmv[/link]