Can't speak to the Duramax but I did an Edge Programmer on a F250 and what a difference!
2000 F250SD SRW 7.3 Long Bed Extended Cab Air Bags
2014 Eagle 30.5BHLT
2007 Layton 245LF (sold)
196? Shasta 16ft
Learn from others mistakes, you'll never live long enough to make them all yourself.