Duramax guru, how do you make an 05 shift as smooth as an 06?

[B.A.Ram]

I'm buying an 05 dirty with a hypertech programmer and when you hammer on it, it seems to shift a little harsher than my brothers 06 6spd with a PPE and a transgo jr. Is this due to the defuel on the tuner, or is it really that much of a difference between the 5 and 6 spds? My brothers shifts smooth as butter...oh yea, the truck has 60k on the ticker and is in great shape...if you just roll into the throttle it shifts smooth, you only notice it when you hammer on it.

 

[stroker-smoker!]

its because of the tunner ppe makes great tunes for the d max