A Platinum or Iridium plug will fire across a given gap at a given compression pressure at a lower voltage than a regular plug. This means that a wider gap can be run without overloading the coil or other parts with needlessly high voltages.

I switched to an electronic conversion [Pertronix] & a Bosch GT40 Sport coil along with Platinum plugs in my stock 1200 a couple of years ago.

The gap was widened out a little but I don't remember to what distance.

The engine immediately idled smoother without that annoying occasional miss while running & picked up a few extra rpm while it was at it.
It starts easier, often within one rotation of the crank & runs ever so sweetly.

As for the ignition system, all new electrical parts [cap, leads etc] & it just keeps going & going & going & going & going & going etc. etc.

I'll be using the NGK Iridium plugs in my A13 engine with even more gap since it will have a HEI distributor from a Series 2 Bluebird.

Platinum or Iridium plugs? I never leave home without them.