Product review (5 stars): I think the filter is working just fine
How do you really know how well a filter is working other than clear and fresh water coming from the fridge.  The price on these is terrific so why not give them a try.  One caution, run a few gallons through the filter to wash the charcoal out.  The water will be real dirty the first few run-throughs.  A two pack for this price?  Worth it.