These problems are only related to the Prestolite kit. I cant comment on other Pertronix products. If you Google "pertronix failures" , you can draw your own conclusions.

From an engineering perspective - I believe the random misfire is due to 2 design issues.
1. The module triggers off of the stock lobes for the points. As you probably know, these stock lobes are a rounded profile and make it very difficult to get a consistent clean trigger signal. (ie this kit does not have a separate trigger wheel with sharp trigger edges).
2. The gap between the lobes and module keeps changing because of the loose clearances in the plastic "bearing". As the vacuum advance module pulls on the module plate, it also changes this gap.
I dont see any way to make this work. Simply too many design issues to sort out.