I'm going to try the new E3 plugs when I get my bike back together. I've tried the iridiums and they didn't give me much over the standard NGK.
Model number for the E3 we need is E3.36, at least that's what their crossref says. I will see. They cost about the same as the premium iridium plugs, $6 a piece. http://e3sparkplugs.com