My dad had an 02 Excursion with the 7.3, and it was, like stated above, the ultimate SUV. Towing capacity was phenominal, it moved that tank like a 1/2 ton chassis and it still would get 25 MPG untuned on the freeway.
The DuraBurb is a pretty sick conversion. Seems like they have made a huge effort in making it a reliable product, which is great!
For the OP. First of all, I believe GM doesnt put a duramax in the hoe's and Kons for a few reason. First of all, our trucks are on 1/2 ton chassis. The duramax and allison marriage is a hefty weight, not to mention the vibration for such small components. Say GM patch that theory. Then comes cost of the vehicle. Its like a $15000 option. GM did right by grabbing that "isuzu" motor and that allison tranny. It had a hell of a run. Ok, so lets say the cost is back down a bit. Then comes the modern day problem. SMOG. GM is turning loops right now as well as the other competitors trying to make sure these diesel motors are smogg-able. They need to burn cleaner and cooler. Extremely untypical of a diesel motor. GM now has a canaster that needs to be refilled at every oil change by the dealership that cost $65. The canister holds "lighter fluid", so that when the collector get full of soot in the exhaust, it heats up, shoots the fluid, and "cleanly" burns the soot.
LOL... that is just three reasons why they never put the Dura's in the hoes and Kons...