They are awsome, I have one 240 in my 28g and plan on having three 425's in my 120g when its up and running. I love how they disperse the output as oppose to shooting out a jet stream.
I know, I guess if you were going for a stream type tank it might be fitting but I'm glad I didn't go for the higher flow. This little 240 is more than adequate for my 2ft long tank.The majority of power head size recommendations baffle me. I have a 72 gallon and bought a 750 based on reviews. My plants bent in half. I will likely end up selling it. If I get anything, it will be a 240. 2 if needed but I doubt it.