I don't have a 2500 yet, but I'm planning on upgrading from my 1500 this fall, or whichever year the updated cab comes out.
The max I tow is ~6k and I'll be towing for work 4-5 times a year up and down the east coast and going as far west as Chicago. I don't like towing with a gas engine, so it's diesel all the way for me. I won't be near the payload or towing capacity limits on the truck, but it'll be a daily driver so ride quality is important. Ergo, I'll move up to the 2500 for ease of towing compared to my 1500. No real RVing in our future, maybe a rental a couple times a year, and that would be well within the 2500 limits, too.