Altho Platinums and Iridiums are for OEM and longevity, my last engine was burning a bit of oil so the Iridiums were wasted on it. Copper's cheaper and provides better spark so I use copper now.
NGK Blue leads are another alternative but I dunno if stock might be better.
Ultimately I think OEM is made for the masses. In most if not all cases OEM is always best for normal people but if we are knowledgeable I say we are entitled to play around a bit eg spark plugs, tyre pressures etc