When you are talking about durability difference between F250 and F350, you can also argue that Stewart Stevenson M1078 is even more durable with even more payload capacity. What are you really comparing the durability to? Is it your past experience? Is it some one else's experience, not a story but actual experience.
What kind of research are you doing to accurately reflect the durability for a vehicle? If you are looking at message boards, then you are reading a fiction novel written purely for entertainment. If you are actually looking at the manufacturer's specification and un-biased companies that give you actual numerical values on the strength, and durability of the part based on actual tests in a controlled environment then you are on the right track.
Are you comparing an F250 built in 1970 to a F250 built in 2010?
You can find a Raptor for under $20,000 online. Supercharged 5.4 Raptors are more difficult to come by and I would avoid them but any 6.2L Raptor will be solid. Why are you worried about the payload capacity? How much are you realistically expecting to carry in the back of the truck and do you think your driving will change when you have a 1-2k camper in your bed? Ford SVT division builds vehicles to a higher quality level than any run of the mill truck. I am a GM guy, have 3 in my driveway, however I have owned two Fords both of which were SVTs and I will be buying the first Raptor I see under $10k. It's a unique truck that will end up costing you much less in the long run and will be more enjoyable to drive.
I built a 2000 Suburban 1500 with 37" tires to be my reliable FAR FAR FAR off the beaten path off-road adventure machine for my family. There is no aftermarket support for them because they are not fun or sexy like many other money pit trucks. I wanted to find out why, no one gave me an actual answer. 5 years and 180,000 miles later I still put 100-300 off-road miles on my truck every week, it's still my daily driver and it still has not yet left me stranded on the trail.
Moral of this is that it's fun and entertaining to pick other people's highly biased brains, however it is your truck, your adventure, you have to write your story. Many will discourage you from a powerstroke, but if you have set your mind on one go for it, get it, and adventure away with it. It's way more fun to be broken down in a truck you love than to look at the truck you don't like sitting in your driveway.
