I've found slop in the metal arms, we started using heavy duty plastic arms here in TX. I can't guarantee it, but in many cases I've seen with my own eyes the servo blamed for the little bit of slop to actually prove that in fact it's not the servo and something else. I always tell someone to go back and re-look at it 5 times if they have to, there is almost always something more you can do to remove slop if it's there. That being said, on the eurofighter, that was the worst airplane to try to get slop out of because of the flex in herent in it's hinging system.