i once read an old post from another forum about the Fluval 404.. theres some issue about the design of the filter and thus people stop buying them because it had a high mortality rate... and its also a reason why it was changed to a 405..
I've once visited a LFS that still had an unwrapped Fluval 404 sitting on the shelf.. dusty and unopen.. price tag is still $200.. but no one seems to buy it..
I agree that EHEIM does have some flaw in certain series of filters.. thats is why there are more than 1 series of EHEIMs.. However.. with that said... The reason why i've single out Fluval is because fluval has the design flaws... even FX5 does have a flaw in the filter.. I recommend visiting the EHEIM pro 3 vs. FX-5 review.. there are some issues with the FX-5 in terms of Long term usage..
http://www.monsterfishkeepers.com/forums/showthread.php?t=68458&highlight=FX-5
I can tell you the issue after reading the full review myself 4 months ago went i choose the EHEIM pro series over FX-5.. i planned to get one.. but after researching and understanding the burned out motor issue.. i decided to go EHEIM..
I can say that if i'm a consumer and after reading reviews of troubles with Fluval brands.. i wouldn't invest in a Fluval if other consumers have purchased it and have issues with the filter.. Just like the Toyota company.. Once a design flaw in a brand has surfaced.. it will loose the people's trust in the brand.. no matter how much they "improve" the product.. I do not want to see my hard earn money go to waste if a product has defects..