The Power Wagon only had the Hemi engine! No Cummins. Otherwise, it is a formidable off road truck. I'm partial to the 5.9 Liter Cummins because you can run Biodiesel without problems. The 07 and up 6.7 is Ultra Low Sulfur only.
I get 20-21 MPG in mine empty and about 17 MPG with a 10K Lb. trailer. It's not a stoplight racer, but with 610ft.-lbs. of Torque I have pulled a 24k lb. trailer and just eased my foot off the clutch to get rolling! I'll keep that thing 'til I die!

 

The Power Wagon is built on a 2500 frame in order to get the benefit of a solid front axle. The Cummins motor requires more room behind the front bumper for the intercooler. The intercooler takes up too much space for the hidden winch in the bumper. And I agree that the 2009 front end looks much better then the 07 and 08.