There was a wave box (demo unit) at my local LFS yesterday (Belgium), The tunze guy was great took time out to demonstrate the unit and had a great chat with him on the new products ETC ( great service yet again, he realy took the time to talk) Anyway the wave box is very impressive, gives a tank a whole new look and realy does get all the crap into the water coloum.
The tank had two 6100 ( 5 foot tank) on it however when the wave box was set up you could see the the current moving dirt from under the rocks, and its silent but the tank did have a central overflow. Just need to find a space in my tank for one.