Done a lot of exhausts on my previous Rams, have also done "exhaustive" research.( No pun intended, ok, maybe a little) While the manufacturers are optimistic about their horsepower claims, this is what I found.
Found a guy here on Long Island who does a TON of performance exhaust work. On my 2015, he did a complete custom stainless exhaust. From his experience/expertise, he removed the old exhaust, extended the main pipe back and installed the Flowmaster for improved scavenging. He then created a new larger diameter Can't remember if he went from the factory 2 1/4 to 2 1/2. Anyway, he enlarged everything aft of the Flowmaster by 1/4". Everything mandrel bent, new hangers, and he enlarged my factory tips to fit. Removed the resonators, etc. Sound was incredible. Not obnoxious, beautiful sound at idle and cruising. 8th gear on the highway was perfect. Loud only when you stomped on it, perfect. Installed the S&B cold air intake, noticed a significant amount of power and mileage gains prior to installing the Diablosport tune a year later.
Price? $550.00 WITH the muffler.
He's currently working on his formula for my '19. All I'm saying, is ask around. These performance exhaust guys might be less than you think.