JMP's Tom Cook designed the Dynamax unit with the help of some engineers that were air flow engineers at GE.
The unit was acually running in an under performance state till the OS 91 came about with the additional horspower.
The unit does run a little more RPM than the ramtech, but it is at the design RPM of the OS91.
The Dynamax puts out 15lbs of static thrust in the 21,000 to 24,000 RPM range.
I think the Dynamx will give better performance both on the low end and Top end power.

Hope that helps
Marty O