I have to partially agree with you on that one, let me explain further...
A friend of a friend is a small engine tech. He bought a 06 5.9. Eventually got it tuned, exhaust, intake, etc. It was a very strong motor, fast as hell too. But the truck had no backbone at all. Everything was cheap and he admitted it. After only 5 years of having the truck it seemed like it was something else every week. Amazingly the trans held up as long as it did. This was the main reason he got rid of it because he knew it was about to go. He looked at Fords but was convinced that Dodge had come a long way, which they have, and was also convinced that the 6.7 cummins had all its problems worked out. Well he's had the 2011 6.7 truck for a little over a year and has had multiple problems with not the truck or trans but the motor. Keep in mind this truck is all stock, doesn't tow much, 4X2 megacab longbed (sleeper). Its just a daily driver and grocery getter. Its been to dodge a countless number of times for stupid little problems but their still problems. I don't know the details but still. Now, he says the Dodge truck isn't too bad (its no Ford) but the new 6.7 cummins just isn't the 5.9. His tuned 5.9 was faster, stronger, and got better mpg, and never let him down. Yes tuning a 6.7 really wakes them up but he can't because of warrantee.
On the other hand, his dad owns a crane company. He had a 04 6.0 as his daily driver. Not studded or anything, but EGR delete, exhaust, and tuned 8" lift on 37s with gears. Nice truck. Amazingly, didn't have any problems except for some bad injectors a while back (cause he let his FICM die). Last year he traded it for a 2012 6.7 powerstroke lariat. Leveled it on 35s and has had it for over a year with zero problems and loves it! Now this truck always has some kind of trailer behind it, works hard, all day every day driving non stop. It has a lot of miles on it and is holding up great and getting reasonably good mpg as far as I know. Its actually quite fun talking with father and son about it because its just such a funny situation between the two, go figure.
Now I'm not saying dodge is bad or fords are non-porblimatic. My 6.0 is at Ford as we speak for an unknown problem. Truck just won't run, but I still love it because its am amazing truck and I would never even consider a Dodge just because they are not proven. (the trucks and the new engine).
Dodge
5.9s (Great motor, not too good a truck)
6.7s (Ok motor, so so truck)
Ford (i will use 6.0 for comparison, simply because I don't know much about the 6.4 and it wasn't ran for very long).
6.0 (not too good a motor, great truck)
6.7 (so far so good motor, great truck)
:dunno: just my $0.02
Good luck with whatever you choose!