@ Timmy - the 190 pound guys can ride it well the 220 pound guys, there are probably better options out there. The original board was tailored to James who is 5'8" and 155, those "dimension" are the best fit for that board. I ride it at 200.
The physical dimensions between the two boards are as Greg noted, the prototype is slightly wider with a tad more nose rocker and it's thicker across it's entire surface, resulting in the thicker rails and nose.
The construction of the two boards is similar. The differences include the carbon fiber tape on the rails, we've skipped that on this prototype, the internal layer of reinforcement is a tad heavier on the prototype and the materials used are specific to the country of manufacture. The skins of both versions are a cross linked PVC, but the one made in the USA is Divinycell and the one made in Thailand is Herex, I believe.
There is a little confusion about the fiberglass and epoxy. Epoxy is a resin and it's used in both boards, fiberglass is a reinforcement and it's also used in both boards. Both of the boards are of a composite sandwich construction, meaning they use a low density foam core to reduce weight and increase shear properties, and wrap that in high density skins comprised of two layers of fiberglass and a high density foam skin. That wrapping or sandwiching is where the composite sandwich name comes from.
The construction is exceptionally labor intensive, the core is shaped, then wrapped, then the final finished board is finished shaped and graphics applied. It takes about twice as long to manufacture this way. There are only two or three shops in the US that can build this way, that I know of. Retail for the board in the picture below is about $1,300 made in Santa Cruz, CA, so the Inland version is a relative bargain
I believe the IS Flyboy retails for $800 which is comparable to other high end boards and about $500 cheaper than if you had a composite sandwich custom made here in the US.