My dad is an auto mechanics instructor and has 40 years of drag racing experience. When I spoke to him about the difference between the two plugs, he said something that made a lot of sense. Since electricity always follows the path of least resistance, the spark will NOT split simultaneously between the two electrodes on dual (or triple or quad) side electrode plugs. The spark will always jump to the side that is closest to the center electrode until there is carbon buildup on that electrode, then it will jump to the other electrode. So there is probably no performance benefit to a multiple side electrode plug, but it may last longer because the side electodes only see some fraction of the total spark events during the life of the plug.
Thanks for the feedback.