I have owned seven Cummins trucks, the first being a 1996 Club cab 2500, then 1998 shortbox cummins stick, then 2001 longbed, 2003,2005 3500, 2007 2500 longbed.In 2012 I purchased my present 3500 Cummins 4WD long bed. I would upgrade as the years went by, and got great service out of every one. One thing I was told by Cummins with my first one, these trucks need to work. If you don't work them, they develop a memory of carrying the weight they are carrying. So Periodically the truck needs to be loaded up, beat like you stole it. When I did that, the truck would perform exactly as Cummins explained. If you dog it as transportation, they eventually slow down in the performance arena.
I love My truck with 10,000 on the rear and driving across the rockies at 80mph
The higher I went, the faster it would go. Yes the 3500 is pretty bouncy empty, but with 2,000 in the bed and my trailer things smooth out beautifully.
Keep in mind the two 3500 trucks (Gas vs Diesel)are not the same truck, the Cummins is much stronger than the gas version.Thankfully, I lucked out, and bought it in Jan 2013 as a 2012 and it had no DEF requirement..
That being said, if I could afford a second truck, I would buy a 6.4 2500 standard cab to travel with when I am not pulling what I normally pull.
One feature the Cummins has that I rely on is the Exhaust brake. Combined with tow/haul the truck goes down the mountain side in safety and ease.
regarding resale, I paid 39,800 for the truck when new, and it would go for 30,000+ any time I chose to sell it around here. Keep in mind it has only 60,000
presently. The gas version would go @ 18-20k tops.