Coil Voltage

The reason I am asking is that I saw an article on how how much better the HEI system is and that it delivers full voltage to the coil at run. No ballast. This article was showing Mopar and Ford guys how to convert to HEI using their stock distributors as the signal. Claiming to provide better performance. I have a friend who actually did this and hid it all inside an orange box. Wondering if theres any performance gain for the trouble.

Spark It Up: How to Convert a Ford or Mopar Distributor to GM HEI