Generally HP is considered to have access to more tuning parameters then Diablo.I bought the HP program just for the tranny tuning,plus the fact it'll work on my wifes 2016 Challenger,once my cheap ass buys the unlocked PCM for it,lol.But I let my tuner do all the tuning,as he's been an HP tuner for 15 years,and i'm scared i'd screw up his handi-work.I've been HP tuned for well over a year,and i'm very happy with the tune-up,but the majority of that is my tuner,he's got close to 30 hours into both dyno and data log tuning my truck,helps he's a very good friend,and loves my wifes baking,as it hasn't cost me all that much for all his time invested,lol