I haven't used the TUNZE products yet, but my next SPS tank will have a closed loop and a stream with a controller.
I used to have a 4x2x2 BB with an ampmaster3000 hooked up to 2 1" seaswirls with 1000gph for the sump return.
The way I had the tank planned out was to have ALOT of flow in the upper and mid column of water. Unfortunately, I didn't think about the BB tank needs, and I ended up having to do more manual removal of detritus off the tank bottom.
If I redid that tank again, I would have the closed loop returns ALL bounce off the bottom of the tank, and put a stream or 2 in the mid water column.
The seaswirls were not as great as I had hoped.