Copper is best conductor, almost as good as gold,and less likely to overheat
Platinum and iridium don't conduct as well and can overheat. They may last twice the distance if not overheated but cost 6 times more
Copper- best performance. Shortest life $5
Platinum- ok performance. Ok life $25
Iridium- ok performance. Better life $30
There isn't that much in it really performance wise but big diff in price.