I think they're OK, but they're tough on pumps IME. If you get it, I suggest using Maxijets powerheads with it as they seem to last well on a wavemaker (not all powerheads do).
With the very high amounts of flow we set up reef tanks with these days, personally I find there's plenty of chaotic water movement in the tank with or without a wavemaker so I don't bother with them anymore.
I actually have a unit lying around that I keep forgetting to sell... :wink: