I can chime in here.
I've always owned gas vehicles and they've all served me well when used and loaded within their intended limits. With that being said, almost everything I've owned got lifted, bigger tires, accessories, mods, etc. Once that happens you take a decent hit in power and mpg. But I was used to it and accepted it was part of modifications. I've also done quite a bit of towing with all of them, and that part sucks. Fine for level ground or small inclines but long grades, gusty wind, unexpected panic stops and gallons per mile made it a absolute chore. Now, I've never owned a full size with the biggest gasser option or any of the new turbo stuff and I'm sure there's a difference there.
A big part of selling my built Tacoma was the thing became a pig to drive. Just the bumpers, drawer, rack and aerodynamic hit really made it not great to drive for anything other then a off road trip. Even then, when it was loaded up for one it felt maxed out. Add on the RTT, lights, fridge, firewood, camping gear, people, extra gas, water, etc etc etc and it's almost too much. Cruise control was worthless, wouldn't hold a gear on any sort of grade, gas mileage was a absolute joke, would smoke brakes within 10-15k and cross-winds were sometimes pretty scary. Then having to tow my boat with it.... LOL. Yeah, not fun.
A buddy of mine has always been into diesels and on occasion through the years I'd get to drive his rigs, unloaded as well as fully loaded towing. It was a real eye opener on how different and
comfortable it was to drive in both configurations. Unloaded, the diesel would just glide effortlessly and appear to sip on fuel. Loaded down, the diesel would still just glide effortlessly and maybe use a little more fuel. But there was no white knuckles, no getting a run at grades, no stopping constantly at gas stations, no worries about being able to stop and it felt sure footed at all times.
So the Tacoma sold and I bought a 06 F350. Not as a Tacoma/Overland/Off-road replacement rig but as something that can do everything pretty damn well. And it's done so thus far. I absolutely LOVE driving it. It's also in the early years of diesel emissions so it's only got a basic EGR system and a catalytic converter which is a big plus.
The power, room, fuel range, bed space and driving characteristics make driving so comfortable and enjoyable. And it doesn't matter if you're flying solo or it's loaded to the max, "it don't care".
There's down sides obviously, but I knew that going into it. Less off-road opportunities, maintenance, repair and a overall increase in cost of ownership.
I do all my own maintenance and repairs and the common parts aren't too far off from the gas counterparts. There's more to them of course, but not paying a "diesel shop" and parts mark-up for a medium/heavy duty truck makes it not so bad.
It'll be REALLY hard to get me back into a gasser truck, that's for sure.