That data does exist, and was published in a German magazine several years ago. Ralph Ploenes conducted the experiment in a wind tunnel, and compared the static and dynamic thrust performance of the Dynamax and Ramtec fans /w OS 91 at various forward air speeds.
The conclusion(s) could be summarized as follows: With a correctly sized/match inlet and thrust tube area, the Ramtec did, indeed, deliver more static and dynamic thrust when compared to the Dynamax with identical inlet/exhaust geometry.
However, if the inlet area dropped below a certain value (can't remember the number) the Dynamax would produce higher thrust levels than the Ramtec.
So, if the inlet area on the jet is on the low side, the Dynamax is probably the better choice. But for installations that can provide the required inlet/thrust tube area, the Ramtec is the way to go.

Peter