After owning several different diesel trucks it all boils down to what the truck's primary use will be. Chevy is obviously curtailing to the occasional towers who want a quiet, clean burning truck, that rides smooth, is easy to get in and out of, and will tow a 5th wheel occasionally...great truck for that. If you need a plow truck, tow monster, all around work truck...I believe the Cummins is the way to go. My 99 7.3L Powerstroke was a great compromise of both and, to date, the best truck I have ever owned! I had to replace the typical wear items that you would experience with 280,000 miles of abuse, but the engine, transmission, transfer case, even the u-joints in the driveshaft were untouched. It needed glow plugs, a new oil pan, power steering pump and a few other odds and ends, but it was still a great truck and still looked good.
My new Dodge, on the other hand, has a great engine and transmission, but the rest of the truck doesn't come close to the quality of my 99 Ford. Dodge now has about $20,000 into warranty work and it goes in again this week. Last week, at 34,500 miles it received all new front axle guts and a new rear driveshaft, and, of course, the computer was flashed again. Now my fuel mileage is UP TO 13 mpg from 10.5. All of the new emissions junk is ridiculous. Our politicians decided that it is better to burn 30% more fuel to get approximately 5% less emissions. One new turbo, two new exhaust systems, countless flashes and axle parts....the list goes on. I am not going to be able to afford the truck once it gets out of warranty. The 6.7L Cummins is faster, quieter, and tows better (all around better engine) than my 7.3L but at what expense? Another point, the Dodge's price tag was $15,000 less than the Ford's, and, when I bought it, the new Ford diesel wasn't out yet. If I had to do it again today, I would have to buy the Ford. You get what you pay for.
After Ford gets done fixing all of the little glitches in the their new diesel, it will be the truck to get hands down. They stole all of the technology from BMW on their latest engine, now they just have to get up to speed on getting it to work right and to last 300,000 miles.
My point being, the new diesels are getting harder and more expensive to own and the fuel mileage is not good. For a work truck that no longer has a warranty, strongly consider a 99-02,03 7.3L truck or an older 12V Cummins (my old 12V, once the tranny was built, was a great truck for towing, just slow in city traffic) if you have to have a diesel.