double strap spark plugs

If you want to blow money, By all meaans, get them. The iridium plugs offer no benafit, other than allowing a little longer interval between changes. Keep in mind how electricity works. You can buy plugs with 47000 grounds, but the spark is going to follow the path of least resistance. SO, your still gonna get 1 spark. When it comes to plugs, the important things are:
Resistance
Temp range (Too cold, and carbon builds up, too hot, and you get detonation)
and gap. A Larger gap gives a bigger spark, however, too large of a gap compromises reliability of the spark itself.

 

What about it?

 

My oppinion is this: Checking your spark plugs is about one of the best ways to see how your engine is running, aside from doing an oil analysis. 30k miles is a good time to replace the plugs, as the gaps degrade over time (reducing performance, less so with Platinum, or Iridium plugs), and by pulling them, and checking them, you can find issues that may be arising. Plus, changing them at 30k miles ensures your truck is running at its peak.