The MSD ones from USA are indeed pretty good, we used to sell them but they were so expensive after import duty etc nobody ever bought one. LOL

That said, we dont experience ignition related missfires with our kit ever, at ANY power or RPM, but you can sometimes pull another 0.25mm gap from a stronger coil and every little helps overall.

The bigegst issue we find, is peoples coil voltage falling really low due to wiring / charging issues. As long as the coild sees 13v there is no reason to upgrade at all IMO.