I read a lot of people stating the XP's are easier to maintain than the fluvals. Could someone elaborate on this? I am not sure what makes them easier to maintain. As for me, I run 4- 404s and a 204 without problems. I maintain a tank for a guy who has an eheim. I am not thrilled with the disconnects or the metal tabs used to secure it. I don't like that you have to remove each layer to get to the layer underneath. At least the baskets in other canisters make this easy to do.