I use quite a few of those hard, stiff, short metal throttle pushrods. But then, I don't run the throttle all the way to the full throttle stop either. I try to set up my throttles where the servo never comes even close to stalling at the extremes of its movement. If the throttle isn't banging its head against an unmoveable wall (the throttle stop) then it only has the throttle butterfly and spring for resistance which is minimal at best. Banging against a stop, the engines vibration can surely beat the servo up in short order .... even a quality servo. Its all about proper setup.