I have a 2013 Ford F350 DRW CC with the 6.2L and 6 speed transmission. I do have a 4.3 rear end ratio.
I am very happy with the engine in the truck. It has plenty of power and pulls well with good engine tracking. Fuel milage loaded with an AF1150 runs around 9+/- mpg but depends on terrain and heavily on speed. From comments on the Ford boards, these engines are very robust with owners running them well over 300,000+ miles.
I believe the new Ford 6.2L's come with different transmissions on the F250 and the F350 so be sure you get the heavier F30 transmission.
I couldn't find many options out there so I ordered it and got exactly what I wanted.
The only comment negative comment I have consistently seen on the Dodge 6.4L gas engine is that the 6 speed transmission gap between 1st and 2nd was chosen poorly.