I have a 2013 F-250 with Camper and Snow Plow Prep packages (heaviest suspension available from factory). Essentially, it's a F-350 suspension with shorter axle spacers. Gas, 4.30 gears factory ordered, 4x4 Super Cab, 10,000 pound payload with an 8' bed. The only differences that year between the F-250 and F-350 are taller axle spacers and a different spline count on the drive shaft. I installed upper Stableloads (large, rubber pads that let the overload leafs engage sooner) and replaced the factory axle bumpers (jounce bumpers) with Timbren SES (rubber baby buggy bumpers "Suspension Enhancement System"). Many F-350 owners perform the exact same mods. My yellow door-jamb sticker states about a 2,950 pound payload capacity, and the truck is loaded with power windows, locks, cruise, tow mirrors, etc. I upgraded the factory wheels and tires (knowing I would upgrade when I ordered the truck), for better capacity. I saved on the purchase price and my personal property taxes are less, every year.
My truck is overloaded by about 200 pounds, with the truck camper loaded for multiple-week trips, per the yellow sticker. The biggest, and perhaps only advantage, of the F-350 is the yellow door-jamb sticker's higher capacity rating, possibly relieving you of some liability issues if things go horribly wrong. For many, that's reason enough to get a F-350. If I were to do it over, I'd probably use my 20-20 hindsight, and get a F-350. Probably, cost me an extra 3-4 grand, over the life of the truck, but there's that pesky liability issue that goes away. I also tow a cargo trailer with about a 325 pound tongue weight (I leave holding tanks empty and cut down on gear/supplies while towing). The F-250 handles fine (the Timbren SES made a substantial difference in side-to-side sway) and the gas motor (remember, 4.30 gears) pulls like a tractor and takes off from the line like a rocket when the truck is empty.
I was looking to go as inexpensive as possible. Get the F-350. If, for nothing else, peace of mind.