I've had both a JLUR and JL Gladiator Rubi. Traded the JLUR in on the Gladiator. I have a wife, 2 kids and a dog - and for me it depended on the size of the dog. We had a larger dog, around 70lbs, and so she rode in the back of the JLUR. Sadly, she passed away in early spring and we adopted another dog that was about half the size. This actually opened up options as he curls up in a ball and easily fits on a single seat or sometimes in the passenger footwell with my wife, meaning we no longer need a large area in the back for the dog.
On the JLUR, we ran a roof rack and thule bubble as the dog took up most of the room in the back, but with the gladiator I either run a tonneau cover, or if we want to bring bikes and a lot of camping equipment, a roof rack with the same thule bubble leaving the bed open for whatever (though obviously exposed to the elements). The Gladiator is much better suited to our needs. I'm also thinking about grabbing a soft topper, which would allow larger items, but still enclosed storage.
Unfortunately, my gladiator is in the shop for a transmission replacement and I have a ram rebel as a replacement. I vastly prefer the gladiator. It's easier to park, more fuel efficient, rides smoother and the interior is nicer - though part of that is because I have a loaded rubi. The rebel bed has a little more room but not a whole lot and the rear seats have less room in the rebel. I also got put in a ram 1500 crew cab (non rebel) and it rode nicely, had more rear seat room, but wouldn't have the off-road chops to do much of anything. It also has a low spec interior so is honestly kind of crap. Both of the rams had the hemi. More power, worse mileage, not worth it for me as the pentastar doesn't struggle much, even when towing in the gladiator.
In terms of storage, I fit all that you see in this pic (except the plastic chair) in the gladiator - under the tonneau cover - plus a bunch of stuff you can't see that's inside the tent, like two mattresses, sleeping bags, folding table, 2 camp chairs etc. There were only two of us in the gladiator on the trip and the back seat was full of stuff, but we brought a ton of stuff that wouldn't be needed in nicer weather for family camping (like a wood stove, extra cooler full of beer, a few cases of loose beer, winter clothing etc). My buddy also packs like an idiot - he brought a full sized suitcase full of stuff he didn't use and we didn't come close to drinking all the beer.