Duraspark didn't come stock on my truck. EEC-IV did. Both have been problematic. The HEI appeals to me, because I have had trouble with ballst resistors regardless of coil choice. I like the DSII fine except for the ballast. Many people run the HEI and like it. It doesn't matter that the firepower is similar between HEI and DSII. Losing the ballast resistor is good enough for me. Of course, we are all entitled to our own opinions. I don't dislike GM, so I have no beef with using their ignition pieces.