I came into this not knowing a thing about US trucks. I had a 1996 Cummins 5.9L in my 32' boat. Great motor. That is all I knew till I got involved with these forums.
Here in Bermuda anything bigger than a 1/4 ton is too big for our roads which are better suited for golf carts & side by side ATVs than cars.
After considerable lurking reading the tooing & froing jabs over which is best it all basically comes out a wash. Some model years seem to be better than others for one reason or another. We got lucky. Turns out 2006 was a good year for GM & the Isuzu 6.6L diesel. Years later there is no itch to get anything newer. Don't even like the looks of the the newer ones.