Just to let you know up front, I sell them.
That being said, I think it's a pretty cool concept. They are only able to do it because of the shell material they use,(GELOY) it was developed by GE plastics and it is bonded to ABS. The combo is stronger than the traditional acrylic/fiberglass combo and they reverse mold the ABS bottom pan up to support the shell so they are able to go frame free.
Most Mfg. are seeking alternatives to the wood frames, maybe Great Lakes got ahead of the curve. From what I've seen of them they seem very solid but we won't know how that is in the real world for a little while.
P.S. The colors they offer in GELOY are sharp!!