I didn't see any current threads with information regards to these two products that NGK offers, particularly the OE Laser Iridium and the IX Iridium series that NGK offers, since I was curious what the main difference were, I stumbled on a pdf file offered by NGK explaining the differences.

Link: http://www.ngksparkplugs.com/pdf/DYK...idium%20IX.pdf

(note) it may take a while to open the pdf once you click on it, be patient.

Cheers.