Seems like a lot of folks (on this Forum, at least) are looking for a tow vehicle that serves additional purpose besides just towing. With the price of today's vehicles, it makes sense.
I see that it boils down to a few choices.
On the financial side, a decision has to be made as to a budget, future plans, garage space (might be an issue for those in an HOA) or need to build, insurance costs/licensing, future ROI, and, barely, fuel costs. More on fuel costs later.
On the operational side, comfort and driveability, towing capability, future plans for truck.
To aid the decision, I think fuel costs can be eliminated. Most folks only tow for a few weeks, at most, throughout the year. The small difference in loss of MPG over that time is negligible. The total miles driven and actual MPG remain. Yes, if you're driving 100K mi/yr, fuel expense is big. If you're like the rest of us, 20K/yr is typical for a commuter. Let's cipher that out. 20K mi/yr at 20 mpg = 1000 gal. @ $3/gal = $3000. 20K mi/yr at 15 mpg = 1333 gal. @ $3/gal = 3999, a difference of $1K/yr.
MO is that reduced major maintenance, resale value, licensing (possible) makes up for a large part of the fuel differences between small truck and large truck. Beyond that, comfort while towing can be valued, also.
With the current 1/2 ton truck capabilities, 6000 lbs is about as much as I'd take on but I'm not up to speed on the latest models.