It is good to see Ram posting these kind of sales numbers (per this and the Jan sales figures thread). There have been many threads and posts about the Titan XD recently but if I wanted a heavier truck and a diesel I would not bother with something with such limited payload but would be taking a hard look at the Ram 2500. It combines the proven Cummins with the CP3 and a coil spring rear suspension while still providing close to 3k payload. My neighbor has one and it drives well and has a comfortable ride. This guy is a good neighbor, ask him for the keys and he says 'sure, here you go'. :)
Then again I am not really in the market as my current rig is a great fit for my purposes and I plan on getting many years out of it.
Good luck,
Stu