What hasn't been mentioned here specifically, is that the CTD is a mid-size engine that was placed in a light duty truck. By "light duty" I mean "pickup. " "Medium duty" is the F600-F800 Fords, C60 GM, S1600 International sized trucks, w/ GVW in the ~15K-30K range. "Heavy Duty" refers to anything bigger than that.
So what it comes down to, is the Dodges have a medium duty engine in a light duty truck which translates to a ridiculous lifespan on the engine and/or the ability to put out silly power. Both the Duramutt & the PowerSmokes are light duty engines. You'll never see either one in anything bigger than a 1½ ton pickup. The Cummins 5. 9 is possibly the most widely used engine in its class. I've seen 5. 9s in virtually every type of lighter duty construction equipment (pavers, small graders, rollers, compactors, even gensets. )
Yes, the CTD is heavy. So far, there is no such thing as a lightweight, long lasting powerful diesel engine. You either lose the weight along w/ longevity & power or you keep the weight & have an engine that'll outlast & out torque everthing else. Besides, the heavy CTD makes it ride better. :-laf
Also, Dodge & Ford are usin' the same axles now. So that's a wash. GM is usin' lighter (weight) axles in order to increase capacity, but losin' strength in the mix. So, there's area where Dodge & Ford are superior. Back in the early '70s, the only real differences between the Big Three were the body & the engine. They all, for all intents & purposes, used identical drivelines. Dana axles, NP transfer cases (4x4s) & SM trannies (except for automatics). I have Ford hubs on my '71 Chevy K20! Could it be we're headed back there again?
Personally, I don't believe an juice transmission belongs behind a diesel unless its an Allison 7500 or the like. All three (except of course now the Duramax Allison) are usin' beefed automotive style autos, none of which were designed nor ever intended for use behind a diesel. Diesel engines put out harmonic vibrations automotive engineers designing auto trannies never dreamed about. Frankly, the Allison, in being reliable behind a diesel, sucks up far too much engine power, which is why you don't see Allison trannies in over-the-road trucks. They are used in specific situations where shifting a lot is either totally undesirable or unwanted (local delivery, rentals, emergency equipment, etc. ).
What it comes down to for me is which truck is really a better truck (not a truck that is tryin' to act like a car). The Cummins is the far superior engine. Dodge & Ford have the same axles, so the Dodge gets the nod b/c of its engine. Dodge has the GMs beat on engine & axles, so Dodge gets the nod there, too. Ford is movin' to the same front axles geometry as the Dodge (what does that say?). Don't even talk to me about their old "Twin Traction Beam" ******* child they had for years. I used to be a front-end alignment guy & that was an experiment that lasted way too long. GM is still beatin' the same dead IFS-front-suspension horse. It has the wheel travel of Tonka Toy & about the same ride. Its fine--as long as you stay on perfectly smooth pavement & never experience a pothole deeper than 1½". On anything else it sucks. My Dad has a GMC & has finally come to this same conclusion (after buyin' the GMC b/c of its superior ride). Now he's wishin' he'd bought a Dodge, especially given the price of gas & fuel.
If you want a truck that behaves like a car, buy a Ford. If you want a truck to use as a truck, get a Dodge. Why you'd want a GM, I have no idea, unless gizmos like 4 wheel steering (more stuff to break & less capacity) & the goofiest lookin' front grill since the '58 Dodge appeal to you.