problem with Ram is that they have a decent (not great) engine, and the rest of the truck falls apart around the engine. We've had several over the years, they all do the same thing. 5.9 was the last of the good cummins diesels available in a pickup truck.
far as ford? Great truck. Keep it maintained and it'll last as long as the cummins engine will, if not longer. People don't maintain things though, and that is where cummins shines--you can get away with neglecting them more, at least until the truck falls apart. Powerstroke is smoother running for sure, and will usually accelerate a little faster than the cummins will. A little quieter too. And the truck is a lot nicer; although I will say the Ram has come a long way since 2001 which was the last time I OWNED one (I have borrowed, rented, used, and our company trucks were rams for a while too). And the ford rides a LOT better, and I don't mean just a little bit, I mean it's a daylight and dark difference better. We still have a Ram at work, one of the last ones, and we have a 2020 Ford. The ford is faster unloaded (can't say it's faster loaded because the loads we pull differ retularly), it rides a million times better, gets a little bit better fuel mileage (contrary to what everyone says it should be), runs quieter, is a lot more comfortable. The guys who drive regularly always jump in the ford these days and that old ram just sits most of the time now.
Granted these are all 3/4 ton not 350/3500/4500/450/etc
Now gas vs diesel debate for those that care. Boss and I have been watching this pretty closely over the last 2 years. We're averaging 22,000 miles a year on each of the 4 trucks (17 duramax 2500, 19 ram 2500 22 ram 2500 6.4 gas, and 2020 6.7 f250). The duramax is showing overall cost (insurance taxes repairs maintenance purchase price and fuel costs) of $1.38/mi. The Powerstroke is about $1.56 but remember-in 2020 the trucks cost a lot more than they did in 16. Ram diesel is $1.41/mi. Ram gas is $1.22 a mile. Compare the ram diesel vs the ram gas, times 22,000 miles and the difference comes out to $4100 and change over a year. It is no longer feasible to own diesel pickup, not for most of us. If you put a couple hundred thousand miles a year on them, the fuel costs might even things out but for us, it doesn't, and we are replacing the diesels with gas burners. The F250 will be replaced with a new 7.3 when the time comes. Here's the kicker. The duramax has some issues (which is one reason it needs to be replaced), rear end leaking, transmission issues, wiring issues, turbo starting to show sign of failure, one injector, glow plugs, ball joints, upper oil pan leak, etc--the dealer's quoted cost to do all this (and some of it is not listed here) is around $31,000. Old job we had a 2007 3500 GMC duramax DRW; spent $21,600 in repairs on that one. Just a battery cable was a $1100 fix (harness I guess). If you are a personal user, and not a business, you get to just eat those costs. Keep that in mind.
Now you know why the ram diesel and the F250 are going to be replaced; actually may not even replace them just get rid of them. The duramax we haven't decided yet. It's worthless as it is, maybe for parts or something but I figure it ain't worth much more than maybe $2500. May end up fixing a few things and dumping it for what we can get out of it. 146,000 miles. Ram gas has 45000 on it, F250 has 99,000, and ram diesel is 107,000 on Monday this past week when I checked them. They were all purchased new.
myself I have a 2003 F250, 7.3L diesel. I won't own another diesel. Don't make no sense for personal use, unless you have, like Napoleon syndrome or you just like to spend money. If I had known when I bought it in 2012, that it was gonna cost this much to keep going, I'd have passed on it.