Of course, I fall into the "diesel" crowd for obvious reasons.... I own one.
Having had gas and diesel, for comparables... 3500 long bed dually's, by far, for towing, the diesel is superior.
Here's my rule of thumb. Far too often folks get a lesser vehicle because they are using it as a daily driver. Then occasionally use it to tow a trailer of some sort. The tow vehicle is really not "truly" hefty enough to to what they have, but they use it anyway. Now, instead of a daily driver, they are towing a behemoth behind them WITH their family and find the performance is less than enjoyable. Now, they are putting their family at risk. So, I ask the question? What is more important? Daily driver or eliminating that towing "risk" once a year?
Personally, that one time a year tow, for a safe, sound, dependable, trouble free experience, knowing the equipment being used is MORE, much MORE than just "so-so" and "hope it's really ok under a load and my family will be OK" is something that is far more important (to me) than just saving a few dollars as a run-around vehicle. That ONE time you tow, and maybe the very first time you tow, may be a disaster. That is no compensation or excuse to attempting to go cheap. (meaning the less expensive way).
This is exactly why I say over and over on these forums:
“You really need to think in terms of what is the ultimate extreme usage you'll be experiencing with your truck, not what is the lightest usage and hope it's OK when the extreme happens."
Now, you decide? Which is more important? And no one can make that decision but you.
