I have a 2008 Dodge RAM 2500 with diesel. Fuel economy is better than a comparable gas engine for the same power. However as soon as it starts pulling then the delta becomes even greater so the extra cost of diesel fuel is offset by less fuel burn.
As to maintenance... well other than filters I don't do anything to mine. It has been trouble free.
The other advantage is low end torque. When hauling and pulling it is much easier to manage since there is rarely a need to do other than release the brake and allow the engine to simply move the vehicle ahead on its own. There is no wheel spin or need to drive up the rpm to make it pull.
If I didn't have need to pull heavier loads I would opt for the Dodge 1500 with the Fiat marine diesel. It is a proven engine and will require less maintenance in the long term. If you buy and sell vehicles on a 3-5 yr cycle then a diesel isn't for you. Just go buy a disposable truck.
I agree that the Dodges especially need care for the body but it comes with most trucks if you are using them like truck. If you use your truck like an urban grocery wagon and expect it to look pristine throughout it's life then maybe you shouldn't be thinking of buying a truck. It may be you just need a cross over or SUV.