MSD, HEI, or OEM?

Back when GM first went to HEI I notcied they were setting the spark gap at .06 or more. I also noticed they got better fuel milage than others, even at NASCAR. Fast forward to todays production vehicles and you'll find every mfgr has followed suit.
It's my belief that as the quality of pump gas continues to go down we will all be looking for a hotter spark for our older vehicles