I have been using these on some 48" foam aerobats, and a 450 size heli for a couple years now.
I've only had one go bad on the heli, and it failed by getting jitters, ie...not a catastrophic crash. My heli flying is scale 2d, not wild, so your results might vary.
My foam aerobat IS WILD, and I've crashed the plane but never damaged a servo.
As someone else mentioned, they do seem to have a unique post size so only the arms that come with it fit properly.