Product review (5 stars): This was a good price for something that is way more expensive other ...
This was a good price for something that is way more expensive other places.  I have really good municipal water so I can't say how effective it is.  My old one was several years old and I only replaced it because the o-rings had become brittle and it started leaking under the fridge.  When doing the prescribed flush (immediately after install), there was some slightly cloudy water, which I guess is the reason for the flush.  But in using it for the past year, there has never been any taste to the water.