Here's the link to my 200DD build:
http://reefcentral.com/forums/showthread.php?t=1976143
In a nut shell, I run a gyre flow model. I have 2 MP40s on the back wall of my tank blowing toward the front obviously. My return pumps plumbing runs up the back of the tank, and along the center brace. Then via loc-line, return flow is aimed back towards the back wall of the tank.
This has accomplished a few things. It creates a large area of flow about 1/3 down in the tanks water. It moves forward towards the front glass then down over the rocks and coral and back up the back wall toward the Vortechs. If you look at the tank from the left side you can see a clockwise gyre in the bottom 2/3 of the tank.
Now, with the return line aimed at the custom center overflow box, a counter clockwise gyre forms in the top 1/3 of the tank.
I have very few dead spots. Gyres are an opposing notion to having several power heads flowing laminarly to certain spots. It certainly appears that I have less flow, and this may be true. But I am "rolling" the entire body of water creating a larger overall flow rate.
My corals are growing well. As I said, I note very few dead spots. As my corals grow into colonies, I may add some power heads on timers to interrupt the gyres flow occasionally to guarantee some flow into zones that are blocked by the corals.
I hope all that makes sense, and you find it helpful. Please review my build thread for clarification on my poor description.