In the first set of links you posted, THContent, they're all poorly-balanced panels, and one uses rather wasteful orange diodes.

In the second link - it says it's using 3w diodes, but then it says 576 pcs of diodes and 600watts - AKA you're being lied to in the sale or they're under-driving the diodes, which DRASTICALLY reduces efficiency. It is also using wasteful orange diodes.