Diesels have better torque at low RPM, so they pull like crazy while using less fuel, and run cooler too. For me it's a seat of the pants thing. It feels stronger, so I prefer it over the anemic gassers. I'm also convinced they're less prone to MPG drop off with lifts, bigger tires and in head...
Buying mine as an overlander/toy hauler. I've never been a truck guy but the JT has ACTUAL tow rating, and I can haul camping crap, bike crap, dogs, coolers, etc. And I have ZERO desire to use a full sized truck as a DD.