I have an 02 7.3 4x4 Ex. Here are my thoughts....
The Ex is 9000 lbs, and has the aerodynamics of a cinder black. With that, the 5.4 is way under powered for the truck. To help it maintain speed, the 5.4 has a high gear ratio, 4:56. As a result, it's a gas hog.
The v10 is a proven work horse...