Needle wheel VS mesh impeller?

[Delphinus]

I tried both as well. I didn't notice much difference in terms of noise and air volume are about the same (I actually measured with an air flow meter and got the same #'s) but the mesh just does a better job of making smaller bubbles of it all. So there is some improvement in over skimming performance that way. But it's not the end of the world if you don't use mesh in a skimmer.