ive had one in constant operation for over a year and a half now. not a single issue. I find it hard to believe that 5 out of 6 units would fail. If the darn thing would fit in all my cabinets I'd have many more fx5s than I would eheims. I currently own 3 different eheim units, all of which are very good, but i prefer the fx5s MECHANICAL filtration superiority.
-Peter