Dude, I dont have a problem in the world with the duramax. After the disaster that was the 2002-2003 engines they've left something to prove IMO. On all the local pulling contests this last season, the duramaxes won the first couple events and the dudes ended up stretching headbolts by the end of the season. They do have great interiors, far better automatic transmissions than the dodge, and a powerful engine. On the other hand you need a 1/4 mile to turn them around, the steering is soft and mushy, it's an 8 hour project to change the turbo, changing the injectors is fucking impossible if you dont pull the motor, the transmission goes into limp mode (for some people) with little warning...
I'd for sure tak the creature comforts of the duramax over the dodge anyday. I dont have the $15k to replace a blown engine though. I'll stick with the cummins I can replace for $7-9k. Anyhoo, mod your truck... as long as it runs on diesel is okay in my book