<<...there is not so great a load on them (ball links on helicopters)...>>

?????????????????????????????????????????????

You have obviously never seen a competent 3D guy flinging a ten pound 60 machine around, doing the latest amazing manuevers.

The load on EVERYTHING during this is tremendous, especially the collective servo.

I agree with sfaust; ball links are inherently more slop-free, although they WILL "egg out" eventually; especially if they are not wiped down occasionally. Fuel residue, combined with grit, etc., will erode the contact points, just like it does on a clevis.

I use a mixture of both on my planks, but elevator and aileron always get ball links.

Steve