I talked to someone their (the owner?) via their Facebook page a while back. The fred480v eBay store is the manufacturer selling the panels directly. He said they're the same modules as the LG NeON2 400 panels, though the final panel's bit less efficient because of the size and busbar configuration. I got the impression the owner's one of those guys who's better at making things than he is at marketing or e-commerce.
I've had 4 mounted on a travel trailer for a few weeks and haven't seen higher than about 400W, but that's with very suboptimal conditions (probably some shading because it's pretty tight up there, right around winter solstice and not very far south, and tilted at different angles due to the roof curve). I'll know more in a few months in terms of output under different conditions and durability.
They definitely seem great, especially for the price. I think Zamp and Grape Solar have been basically stagnant for years in terms of price and efficiency, but RV makers still use them because they're the established brands.