Product review (2 stars): Quality control issues?
Before I begin, let me state that I live in a Southern California suburb, and the water, while ostensible clean, has a definite taste straight out of the tap.

 I think there may be quality control issues with this filter.  I installed one in my refrigerator as soon as the 3-pack arrived.  As soon as I removed the new filter from its box I could not help notice that it felt noticeably lighter than any I'd used before.  I installed it regardless, and ran the requisite gallon of water through it.  For the next few days various members of my family noted to me (independently) that the "filtered" water from the fridge tasted like unfiltered tap water.  I had noticed the same thing myself, but hadn't mentioned it to anyone.  I was hoping (I suppose) to avoid the time and expense of replacing a just-replaced filter. Nonetheless, after two or three weeks, everyone in the house was asking when I was going to do something about the water.  There were still two filters left in the three-pack I'd purchased, so I took another filter from the three-pack (noticing that it did not feel nearly so light as the first one) and installed it in the refrigerator.  The water now tastes as fresh and clean as it did before the previous filter change.  I'm guessing the first one was lacking sufficient material to properly filter the water. I'm wondering what the third one will be like; it's unlikely that I'll buy these again