currently have 2 Emperor 400's on my 55 Malawi tank, they dont have much options for media and are a little loud. Other than that they work great keep the water really clean and I am having no problems with them now. I want to get either a Magnum 350 with the Bio-wheel or a Fluval 404. Has anyone had any experience with these filters and how did they work? Or should i keep the ones i have because I am somewhat happy with them and they work fairly well. What would be the advantages to switching to those filters.