You can also get the honeycomb panels injected with foam, which gives you the rigidity of of honeycomb with the R value of 5-7 per inch depending on foam type.Thanks for the link. I have inquired with a couple different manufactures. Some make limited sizes, some only make the honey comb panel. Personally I would prefer
the sandwiched foam panels. Andreas seems to have the total package. He even has a method so the walls can support items such as spare tires,
racks, etc. This is also important for attaching interior cabinetry. As a DIY , I need to keep it as simple as possible But I sure wish I had Mark's toys..
Here is some info Andreas shared with me;
Extruded Polystyrene (blue foam)(XPS) has an R Value of 5-5.4 per 1" thickness
Polyurethane (yellow foam)(PU) has an R value of 6 per 1" thickness. Compare to the XPS it will break down sooner (15-20 years) but can handle chemicals better (like polyester resin)
PP Honeycomb has an R value of ~ 2.5- 3.5 per 1" thickness
You may get away with the honeycomb panels for 3 season camping but when hitting sub freezing temperatures your heater will run a lot more often or you will even get condensation inside the cabin.
As for the weight differences: Honeycomb is about 10-15% heavier but more rigid. (can handle impacts better)
At the end it comes down to your preference and the intended use. But I always mention that 99% of all the expedition trucks are constructed with PU or XPS. I only came across the honeycomb here in North America as a building material.