I dont know about the newer boxes, but on the older mechanical engines, they were quite vague about what they did, and never gave me any satisfactory answers. I was towing a GCVW of 24K last winter (hay on a BP flatbed trailer), and ate a Dr Performance 2nd Gen towing a TT (had Dr Performance on the side, kinda like a Banks stickers on steroids) on I-70 in eastern KS. I was in a 93 D350 with STOCK injectors, STOCK turbo (w/12cm housing), and some modest pump tuning- made about 28 psi peak.
One other thing that got my attention was they claim to not add fuel, they just atomize it better. That is good for <50 hp. You are NOT going to gain 100, 120 or more HP without adding fuel, no matter what kind of wizardry you perform under that hood.
They also claim that since their fuelling is so efficient, there is no need for a pyrometer. B. S. Need I really say more? It is my personal opinion that ANYONE running a turbocharged ANYTHING needs a pyrometer. It is just too cheap an insurance against a melt- down. ANy company that tells you you dont need one is doing themselves- and you- a disservice.
I cant tell you to get a DrP kit or not, But do your homework before you buy, and figure out which is best for you. Ask questions, and if it sounds like a bunch of snake oil hype, it most likely is.
Daniel