My unscientific observation of the two styles of ignition packages is: the Magnavox type has more issues with overheat and melting of the potting material in the ICM, on the other side, the Delco style has more coil failures. The Delco style does produce a more energetic spark, which has been demonstrated in the past, but coil failure may be the side effect. In any case, I have heard recommendations that the coil(s) be replaced at the same time as the ICM in both styles as a defect in one part of the package can overstress the mating piece. I know I have never done so, but then I have changed engines in my car a half a dozen times so my experience is not the norm🙃