I just talked to a fellow at the local gas station today. He was filling up his Ford F350 2wd, dually,crew cab, w/V10 under the hood. Attached to the rig was a trailer that had to be about 30 ft long. It was an enclosed triple axle trailer, and not very aerodynamic by any means. And loaded heavy.
Anyway, I asked him what he got for fuel mileage. He said 15 mpg. My jaw about hit the ground!!!!. I asked him if there were any aftermarket mods done to the truck, and he said no.
I am hoping that if you get the V10, that you keep us informed as to how it performs, and what kind of mileage you get. If it is as good as that fellow said, I would be looking to trade my 04 in. If I could get one that made that kind of mileage, beings gas is cheaper than diesel, I would be waaayyyy ahead.
I personally have never sat behind a V10, so I know very little about them.
Good luck with whatever choice you make.