wow, guess its a matter of opinion there. some love the emp 400s and some love the ac 110s. i have both and like both. the emp sometimes is a bit loud but that could be a scored rotor. the ac you can modify a little to get a stronger flow, i dont like the strainer that comes with the ac nor the lenth of the tube...so i remove the strainer, take a piece of undergravel filter tube and attach it to the ac tube and then take a emp 400 strainer and attach it to that.
mike