Given the large disparity between the published specs and the measured performance, especially given the burst-power graph that the manufacturer has apparently owned, I wonder if this example has some sort of production fault, perhaps in the power supply, that is limiting its performance. The inability to produce anywhere near the rated power has me especially suspicious, because that misrepresentation would be so easy to discover, and would support a complaint to the FTC.
Rick "has anyone communicated with the manufacturer?" Denney