There is a lot of marketing hype about spark plugs. As usual, misguided hopes which result just cost us money, and don’t produce real results.
In my testing, the Bosch +4 and the NGK 3’s only advantage is allowing 4, or 3, opportunities for a single spark path, the one better path at any given time get the nod. That may explain some good impressions about the plug, (i.e., a spark path more easily presents itself) but I ask, at what cost? …and why? …when far better spark technology is available. This technology makes marginal most of our mussing about plugs. However, I would recommend NGK because they have the finest ceramics, are well made and are not too costly.
MB spark is amongst the highest energy in the first place. However, ever seen most sparks at the plug? Add the effect of compression, and things seem even less impressive. The bottom line is that we are trying to affect as many air-fuel molecules at one time to effect a positive ignition each and every time. Nothing more, nothing less.
The way to affect the most air/fuel molecules is with increased energy, not increased duration. A stringy spark lasting a longer time still affects only a fraction of the air/fuel molecules than the massive plasma sphere produced with a peaking capacitor. It ignites the leanest and richest of mixtures, and one does not have to use costly spark plugs with multiple spark pathways. Install DirectHits and stop worrying about the performance of your sparkplugs.