Mine is noisy and the output ramp thing (where the waterfall flows down) doesn't extend down far enough. Because the tank I use it on has a corner overflow, the waterfall falls too far and makes more noise. I fixed that with a sheet of filter floss now, and the sump is louder than the AC110 so it doesn't bother me. Nicer filter I think, but from my limited experience with it I think its over rated.