Copper foil dot the contacts....never have to worry about it again......Also, for games that use analog style controls they work very well....but games that need digital style control they're not as optimal. For what they are inclined to do well with YES they do very well......in spite of that, a fixed one will still work for digital games...The 5200 should have come with 2 types of controllers....the original for analog style control, and another for digital.
Missile Command is for example...best played with the Trak-ball.....but if not...a 5200 controller will destroy any digital controller in that context.