Product review (2 stars): Got a defective one.
Usually these are really reliable.  But, odds are  if you buy enough of them you are going to get a bad one.  Well I got a bad one.  There must be something loose inside the filter as from time to time it seems to plug up.  This causes very little water or none at all to pass through the filter.  If you wait a while it works just fine again.  I would hope that the manufacturer would provide a replacement but to make sure that water is always flowing to the ice makers (the refrigerator has two) I have had to buy a new one.  I have never had a problem before and when they work it really makes the water taste better.