I used the iridium for a while but didn't notice any difference in performance.
I looked to see if the more advanced triple, quad exotic whachamacallit plugs from Bosch come in size and spec to run in the Rocket but last I checked, maybe six months ago, they didn't have anything compatible.
I'm interested in checking out those pulse technology plugs next, like that Pulstar. It doesn't look like they have a compatible plug though.
Our plugs are 12mm thread, .75 inch reach and rated for motorcycle use (high RPM, high temp).