I have the RENA XP and have no complaints at this time. I have only been using it since first week of February so not sure about long term usage yet. So far, no issues. It runs very quiet and I like that you don't have to prime it after the first time. There is extra room to put floss in as well if you want to polish your water. After using HOT Magnum's for 3 years, it is nice to have a canister filter underneath the stand. I am also using it as a reactor for my CO2. Great convenience there.