Weezle, true, looking at the high end, jets, giant scale, etc., where flutter would be a total disaster, the issue is generally circumvented by proper selection of servo and linkage and good building techniques such as decent hinges, proper installation, and minimal hinge gaps. Basically everything mentioned in this thread EXCEPT the mass balance. You will rarely if ever see mass balances in jets/giant scale 3D, etc. This is because the mass balance often creates more problems than it solves in our models due to the lack of stiffness in the control surfaces, which is in turn due to the building materials we use.