I just traded in my 2011 1500 Silverado 4x4 extended cab for a 2016 2500 GMC Denali 4x4 Extended cab. I pull the trailer in my signature which was 4100 lbs dry weight and is around 5500 loaded as measured across scales.
I can tell you that by the time we loaded it, put a few things in the bed of the truck like coolers and cornhole boards and an extra propane tank for the grill and outdoor stove, we were within a few hundred lbs of the limits of the cargo carrying of the truck. It was important to have the WD hitch zero'ed in properly and even then, there were times in windy conditions, I wish I had more truck. Going up mountains to the Smokies was bounce between 2nd and 3rd gear with earplugs needed when it dropped to 2nd and reved up until it shifted to 3rd. Knowing what I know now, I would have gotten the 3.73 rear end as I think that would have helped significantly but I have to tell you, I don't even know it's back there in the 2500 now.
If you can swing the extra a 2500 will cost you, I would advise to get it. Much more comfortable towing and lets me load the bed to the brim if I so desire. Wind and semi's passing are non events with the extra weight of the truck. If finances are challenging and you decide to go the 1500 route, I wouldn't get anything but the 3.73.
