I upgraded from a 2004.5 2500 to a 2014 3500 dually when we upgraded to a bigger fiver. Our new trailer is 15' longer and at least a foot taller, but the bigger combo is much easier to pull with this newer truck. I love the engine braking and the smarter tow/haul mode of the trans. Even though we're a big dumb slow moving beast now, I'm still less tired out at the end of the day than I was with my older truck.
The creature comforts are incredible too. I can't believe this is a pickup truck.
We couldn't afford a new one, but we got a great deal on a used pickup at
https://www.texasdirectauto.com/. It was totally worth flying from CA to TX to buy the truck and drive it home.