I will never believe that an octane booster can raise the octane that high. Maybe 93 > 96 ish but not 91 > 100. Their website advertises 91 > 110 oct. I do not buy that at all.
OEM ECUs were not as complex back in the day, but it was easier to run a SSAFC than it was to re-program the OE ECU. Current ECU tech allows for far greater manipulation and control than that system does. I was speaking to my tuner about getting an aux fuel system to communicate with the factory ecu, and it just can't be done. With a stand alone like Syvecs or something it certainly can be though. "If it ain't broke dont fix it" works great for tried and tested tech, but applying 90s tech to cars built in the last 5 or so years is like using a horse to pull your car around, it works but its inefficient. SSAFCs are "batch fire" controllers, that means all 4 injectors spray at the same time and can pool fuel up on the cylinders that are closed, combine that with no way to monitor it directly is asking for trouble eventually.
There have been issues with the single ports, as far as intake side backfires. The same goes for meth injection if the backfire happens while its spraying. I believe in time there will be failures of some type, whether it be the hose, pump, injector seals etc. Its an additional point of (potentially major) failure in the car and I don't think its worth it anymore.
Well thats your opinion and we all have our own. If you don't want to undo the minimal amount of bolts to remove the IM and clean it every once in a while, well ok. My partners fiesta has 75k miles on it, we took the IM off at 52k to check it out and it was fairly clean. Minimal build up that i scraped off with a flat head and some carb cleaner, maybe some sustained high RPM would help you out since its well known to assist in preventing carbon build up.
In the end its personal preference. Before the 30% injectors and pump existed this was the only option, understandably so, but it has taken off in application here vs not as popular overseas and no one knows why.