If you do some research on the web on Iridium Spark Plugs you'll find a pretty consistent 1 or 2 hp gain in most applications. My view of why that is happening is that using them has the same effect as advancing the timing slightly, with no knock conditions.
They do work and are worth a try. Lots of nay sayers but go ahead and try them, you'll be pleasantly surprised.
2013 DL650 Adv