I dunno. I'm cramped in a 10' camper all by myself. I couldn't imagine being stuck in a camper with two screaming, fighting children and an annoyed wife on a rainy day.
One nice aspect of a travel trailer is you can get one with plenty of space for a family of 4, and not have to buy a new truck. Way less invested.
As far as quickness, travel trailer. It takes me a minimum of 30 minutes to load the camper, but only 3 minutes to hitch up the trailer.
I know everyone says, "go anywhere," but with an 11.5' behemoth camper on a dually pickup?
How much offroading are you *REALLY* going to do with a rig like that?
Everybody knows "duallys are worthless offroad," and the huge heavy camper is not going to fare well being strained through trees, bounced down rough roads, and twisted through off-camber terrain.