If you are looking for improved performance or better fuel economy, you will not get it by paying extra for exotic spark plugs. If your spark plugs are really buried and you don’t ever want to have to replace them again, they might just be worth it. Platinum plugs are plenty sufficient for most people. I have replaced platinum plugs that had over 100k miles on them and they still looked like new. I say for your Silverado 1500, use whatever the factory specified, even if it calls for copper core. I can’t think of a single Silverado with difficult to change spark plugs.