In all fairness you can change the media in the Emperor 400 also. You don't have to purchase pads, I use cut foam for mechanical, and 2 of the 4 cartridges are designed so they can hold ceramic rings or bio balls if you wish. It is a little loud, but I have grown accustomed to the waterfall sound and sort of like it. Never had any problems with it, but I run it in conjunction with a canister filter also.