Just traded a Dodge 1500 Hemi for this 2007 2500HD with the Vortec 8100 and Allison six speed automatic. Wow this thing really goes! It is better than the old 454 engine. I needed a lot of pulling capacity but did not need the expense of the DuraMax, this really fills the need. Gas mileage is about 12.5 mpg around town and 14.5 on the highway and it loves regular gas. Drivers seat is much better than the Dodge was. Steering is not quite as good, seems to wander at high speeds. Could be the E load tires compared to the 20" tires on the Dodge. Attention Dodge owners: Chevy dealers will not give you anything on trade if you have a 05-07 Dodge. Overall very strong truck.
Vortec 8100 , Allison Automatic and 4.10 gears make for a real puller.
Bring back a big block gas engine for the new body styles.