I've been looking at a few 6.7 Cummins powered Rams to replace my tried and true 2004 5.9 Cummmins Ram.

I want a well optioned Laramie and/or Longhorn 4x4 crew cab short bed.
This truck will also be my daily driver just like my current 5.9 Cummins is.

From my research it seems like the 2010-2012 Cummins Rams are popular as long as they are deleted and tuned.
The area I live in does not do emissions checks so there are a lot of deleted Rams for sale in my area but these modifications do seem to limit the truck's value and resale in areas that do emission checks.

I prefer the 2013 and newer Rams with the newer electronics, larger touch screens and other options but they do have the added DEF to deal with.

I understand there is a difference in rear suspension and transmissions between the 2500 and 3500 trucks.
Is one setup better than the other.

So which 6.7 is the better way to go.

Are the newer DEF trucks pretty well sorted or do the need deleted and tuned also?

How does the MPG of the older 6.7 deleted Rams compare to the newer stock DEF trucks?
Any chance the 6.7 mpg will be close to the impressive mpg my current 04 Cummins Ram gets?

Thanks.