I think where specific claims are made, they are met. But the additives are not added before the pipeline....they are added at the terminal as the gasoline is going into the tank wagon.
Way back 35 or more years ago, there were very few government regulations as to what went into gasoline, no posting of octane on pumps, etc. I used to work at an Esso (later Exxon) refinery, and could tell you stories that would make your hair stand on end.
Today, however, engines and their fuel systems are far more sophisticated than back then. Moreover, in many areas there are EPA or other government environmental agencies that have promulgated regulations comprehensively defining gasoline specifications on a regional basis, everything from vapor pressure to oxygen content.
There just isn't that much room any more for gasolines to be very much different. I guess alcohol versus MTBE is one area, but then some places have banned MTBE. Oxygenated vs non-oygenated is another.
Other than the additive packages, oxy vs non-oxy, and octane levels, I consider, within a geographic market, gasoline to be pretty much generic in this day and age.