There are good Platinum, Iridium and Ruthenium plugs available, saying one is better than the other is easy to do, but hard to prove. Either could serve you well. Spark plugs are a consumable part, making sure they aren't worn (increasing gap, electrodes no longer sharp) is the important thing.
Remember what you are getting with these high-end plugs are plugs that were designed to be run longer, better wear resistance. Most enthusiast find themselves changing plugs because they feel the need as opposed to there actually being a problem.
I run NGK Ruthenium plugs, they have served me well in all the turbo engines I've owned. I've never pushed a set to see how many miles they would actually go. Mine never see more than 20,000 miles, I'm sure they'd go much longer.