Hallmark is a Colorado-based manufacturer of truck campers. They recently began experimenting with a camper constructed of composite materials. Using no wood or metal, they have built versions of their truck campers with a material called Coosa, a composite that can be worked just like wood (routed, stapled, nailed, painted). The result is a camper that weighs only 50 lb less than Hallmark's design with framing, floor, roof and cabinetry made from wood.
So if there's no weight advantage, why buy a camper built from more expensive composites? The camper will be impervious to moisture, and insects are not interested in eating the bones of the camper. These features could give the the composite camper an advantage in areas with high humidity (like western Washington state and southeast Alaska) or wood-eating insect populations (many places in USA, the Central American tropics, east Africa, etc)
To me, the most interesting aspect of this story is that composite materials by themselves don't save weight. You have to adopt different construction techniques to gain full advantage of the strength to weight ratio of composites.
Hallmark will present the new campers at Overland Expo in May. Definitely worth checking out.
Here's an article in Truck Camper Magazine with more details