Well this topic has certainly gotten out of hand, so I can't make it any worse. I call all of the performance enhancers jokers, cause they must be kidding with their claims, right? Do they ever give detail on their testing method, and performance results? Modern vehicles record performance data, a whole slew of things like all of the EGT's, crank and cam positions, speed and on and on. Don't ya think a good "hunter" can identify what any module has done. You will leave tracks, it just depends on how good they are, and how determined, and how much time (money) the decision is worth. Me? My hunting was though lease custody meter tinkering and royalty payments. Somebody is always just as good, or better than me, or you.
So take their claims with a grain of salt. Admit the costs, and weigh against the benefits. Then test. Then evaluate. Get your money's worth? With a good return of investment? Post and let us know. It doesn't seem worth it to me, the power never seems to end on these modern diesels, but that's just me, you mileage may differ.
In full disclosure, I am a old fart, the first diesel dump truck I drove had a diesel without a turbo (NA diesels, remember those days). It was fantastic compared to the gas jobs. So these modern trucks are just wow, right off the lot.