By "fender mounted module and resistor" I assume you mean the factory Mopar ignition c.a. 1970's. The biggest advantage is that you can run a better E-core coil with much higher primary current. There has been much progress in semi-conductor design since the 1970's. That gives a much more powerful spark, aka "HEI ignition". You can then gap your plugs up to 0.060" for better combustion, especially with leaner mixtures if you want more economy.
Other advantages are much simpler wiring and more reliability. The old Mopar boxes are known the fail often. I also think the "ready to run" distributor pickup is much better than factory Mopar, with multiple teeth that make rotor wobble less of a problem.