The rudder is only as effective as the servo. The stronger the servo, the stronger the rudder. If you want to be able to carve that integrated 2 roll half loop then you need the power.

it also affects the snap somewhat. A stronger faster rudder will snap more violently than a weaker slower one.

Actually this is the one surface on this plane where I have to say don't skimp on a servo at all. You can get away with murder on the ailerons and elevator...not the rudder.

-Mike