Personaly, I think there's a lot of hype in sparkplug advertisment. On a standard engine, with low tech cdi. or points igniton, not racing situation where milliseconds count, there is not a lot difference in performance no matter what brand the plug is.
Electrode /ground design does make a difference though.
The multi point plugs only fire at one point, until it erodes a little and moves to the next closest one, not all 2 0r 3 at the same time. Aircraft plugs are made this way for reliability, in case of a bout of detonation or lean conditon, the plugs won't burn out easily.
Now, Platinum or irridium plugs last WAY longer than standard plugs.
Electrode design does make a difference. I know of dyno tests on Ducati's, that verify that 2 stroke type plugs that have the shorter ground lug that exposes the electrode's do make a 4 stroke run better. The flame kernel gets a quicker start with the electrode spark not being shadowed so much by the ground lug.
Improves even more if the ground lug's end is tapered and radiused with a file.
You can take any standard plug and modify it like this, so that about 1/3 of the electrode is exposed when you look strait at the end of the plug, then taper it some to about 1/2 original width at the tip then round off the tip, and get a noticable improvement in performance, but a shorter plug life.
