The insulation should be fantastic since all of the panels have "vacuum" on the inside of them. Carbon and VIP in one, wow.
(In the commercial insulation world, VIP = Vacuum Insulated Panel, a fumed silica product, sealed in plastic under 0.1 psi of vacuum.) R-values are 40 to 50 per inch.
Here, it appears that the carbon cloth is 'infused' with resin, hopefully epoxy and not vinyl-ester, while under vacuum or being vacuum bagged. This process, called resin infusing, minimises waste by allowing the amount of resin injected to be tightly controlled, which keeps weight to a minimum. On a large panel, excess epoxy can add significant weight; this is common in wet layup applications. The vacuum on the panel also serves to make a nice surface finish and make the panel even, where a wet layup process can leave the opposite.
Neither the carbon cloth, nor the panel are infused with a vacuum, i.e. the vacuum is not left inside or contained inside either. Rather, the epoxy resin is infused into the cloth, kind of like using a vacuum bleeder for your brakes. Remove the air from a closed loop system, feed tube goes into epoxy source, open the valve, epoxy resin soaks cloth evenly.
Simply replacing an E-Glass or an S-Glass with carbon cloth will not save an enormous amount of weight on its own, as the properties are not THAT much different. The weight savings comes from thinner or lighter weight carbon cloth, inherently stronger than E-glass or CSM. Thinner carbon means less cloth weight, which means less epoxy, as the ratios are typically based on weight, i.e. 16 ounces of carbon cloth requires 16 ounces of resin, or whatever the OEM specifies.
Previously, ER used an end grain balsa wood core. While Bill says this is "light and strong", it isn't really either, and it's old tech. To save weight and improve heat and sound insulation, a structural foam should be used, i.e. CoreCell or Divinycell. Further up the scale are products like Nomex, Hexcel and aeroFibre, squarely in the 'unobtanium' category, unless your last name is Lockheed or Boeing.
So let's compare the old EarthRoamer box to the new one. End Grain Balsa has an R-value just R2 per inch and a mass of about 10 pounds per cubic foot. Compare that to a non-structural foam, such as XPS , having a mass of 1.5 to 2.5 pounds per cubic foot and R-value of 6 per inch, or to Divinycell, with a mass of 2.5 - 5 pounds per cubic foot and R-value of 5 per inch, in the 3 PPCF product.
There is a massive weight savings, just from using foam. Of course the carbon helps, but so does not having wood walls. Kudos to EarthRoamer for pushing the envelope a bit; now the guys and gals who paid 500K for Balsa wood and crappy Dometic windows have to upgrade.