x2 on the Hypertech. I've been running one set to stage 3 for about 100K miles on my 01 2500, nice power, zero probs, tows great, picked up 2 mpg hiway to boot. Since I live in the People's Republik of Kahlifonia, its real handy to be able to put her back to the stock map for the biennial smog-check (really...on a diesel?!) Kind of like how we used to disconnect all of the smog crap & crank the timing back in the 70's, then reconnect it all & lean & retard everything every 2 years just for 5 minutes on the smog machine!