Had my 08 2500 reflashed today. What I have noticed is lower idle speed when in gear it now has auto idle to 1100 RPMs when idling when not in gear after about a minute warm or cold ( Never did this before). Better low and mid pull and milage is noticable, as well when engaged the exhaust brake is working even at an idle it used to cut out when lower than 1200 RPM, now it cycles even at an idle when foot is not on the accelarator. Just my observations after 300 miles.

I have to say though my 6.7 has been flawless other than a grill that peeled after being hit by a stone ( replaced under warranty ) and tie rod ends on both sides replaced after 1000 miles with greasable units also under warranty.