Having read all of this thread, the best recommendation I can make is that you sit down and cost it all out. You know your driving habits, you know how long you typically drive a truck. (The fact that you COULD drive a diesel 200K doesn't matter if you only drive it 100k). Once you know the estimated total mileage, calculate the fuel cost for that mileage based on what you believe the two trucks will achieve. Add that fuel cost to the cost of the truck and divide by the total mileage. You'll get an estimated cost per mile for the two trucks.
In my case, I drive a 2002 2500 HD 8.1 Gasser with an Allison behind it. When I pushed the pencil, it figured out that I would have to drive the diesel 223,000 miles to break even. Since I rarely drive a vehicle more than 125,000 miles, it the diesel just didn't make sense for me! And, I'm still towing my Landmark with that 10 year old 8.1.
Just be sure you're thinking with your pencil, not testosterone!!!!