best for spark transfer; dull or sharp edges?

Bewy said
Plat plugs [ & Iridium ] take less voltage to fire. That is one of their benefits & why they are used: less emissions. They have less misfires, all else being equal, because of their reduced firing voltage requirements. This means that as the electrodes erode & the gap grows, they will still keep firing, reducing emissions that would come from misfiring plugs.
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Can you post your information source on that? I've always read that copper conducts better. As a better conductor, it would seem that it would take less voltage to fire, right? The only benefit I'm aware of with platinum, iridium or any other "exotic" metal is that they simply last longer.