I create random chaotic flow with multiple powerheads plus 4 nozzles from my return pump. All for a fraction of the price of an MP40. I grow SPS like gangbusters, and have been for over 3 years. So, if the question is, are they worth it just to grow coral, the answer is, definitely NOT. No one can look at my tank and contradict me. Then come the other factors: low profile inside the tank, lack of wires inside the tank, the "cool" factor of creating all kinds of modes of water movement, and the bragging rights of having one of the most expensive modes of creating water movement. That's where the individual has to decide whether it's worth it or not. For me, the answer in no. For others, as you can see from the above posts, the answer is yes.