I find it more useful than the double cab too. I think the point is not that you can haul 6 people, but you could haul 4 or 5 plus all their gear inside the truck. The JKU can haul two people and alot of gear but with 3 or 4 the rear space is limited. This is coming from the point of vie of someone who travels with mountainbikes, skis, and gear that can take up alot of space on along trip. I know with my 80 series that with even 3 people I have a hard time stuffing everything in on a biking, paddling, overland type trip. I like a large SUV style body as you can put long items in it versus a double cab pickup body style where you have a defined cab and bed space.
I bet you could take that thing pretty much anywhere you want to go outside of dedicated rock crawling trails that lead to nowhere. I am sure someone can think of a trail here or there to cite an example to the contrary but it goes back to what you want the rig for. Rock crawling, trail running or some type of long, supported trip into the backcountry or accross a continent. For those of us who don't want to drag a trailer, something like this is sweet. That said, I am not in the demographic to swing one anyway.