Does yours have points? The factory electronic ignition is more efficient and more reliable than the Dyna S. The Dyna S would be a downgrade in my opinion. The Dyna S is a good ignition and is definitely an upgrade over points, but not the factory electronic ignitions.
The higher-level Dyna ignitions allow you to adjust the timing. They might be considered an upgrade, but I would still prefer a factory Zx or Zr ignition.
The various Dynatek models eliminate the factory pickups, rotor, and igniters. The digital ones also eliminate the advancer unit.
They come with either an integrated igniter in the pickups, or a separate igniter box.
The Dyna ignitions also require different coils (than the factory electronic ignitions).