So, from what I see these eductors/penductors are simply increasing back pressure by narrowing the orifice. This will increase the back pressure and therefore the output pressure.
With this higher output pressure, and therefore output velocity, the conclusion is made that you receive more "flow". Well, not really. What you're getting is more turbulence, more water movement, but not more flow (volume). Actually, you're decreasing the volume by narrowing the output end and raising the back pressure.
In the end, you might achieve a benefit, I guess, by increasing the velocity/turbulence of the water but that's not what I'm looking for in a new tank set up, although very interesting. I'm a Mechancial Engr. by profession. Although I'm a structures guy, I know a bit about flow mechanics..
dual 175 MH
w/ dual 32W PC