It looks strangely familiar...
I can see that you've opted for a center inlet, and a side outlet, like the Atlantis block.
In my design, I would have replaced your pyramid with radial fins, but since I was going to experiment with feeding the water in a spin, the fins are out (they'd also be hard to mill).
This pyramid of yours should be fairly easy to mill. Do you have a mill of your own? You could have the channels within the pyramid directed in a circular pattern, instead of "straight out".
I'm not sure about the angle of the fins on your design. Did you just make that up, or is it calculated, or based on testing?
I've got to get a prototype going... Wanna collaborate?