Product review (5 stars): Good, Expensive
They're good, they're expensive. They work.

My refrigerator filter "idiot light" came on the other day. I decided to try an experiment. I poured three glasses of water. The first was plain tap water (let's call this the "nasty control"). The second was a glass of water from the old filter. The third was a glass of water from the new filter, after priming.

Test number one was the "smell test".

The "nasty control" smelled like "nasty". It was by far the easiest to recognize. The water from the old filter smelled strange, but I couldn't quite put my finger on it. The water from the new filter did not have an odor.

The second test was the taste test. The nasty water tasted nasty, and the texture was actually slimy and disgusting, as if the tap was full of saliva instead of pure water. I had trouble differentiating between the filtered water and the old-filtered water.

The third test was the visual test. The nasty water looked nasty, and was visibly more viscous than the filtered waters. Both filtered waters appeared exactly the same.

So there you have it: The filter takes nasty water and turns it into potable water. The older the filter is, the less nasty it is. They are expensive, but convenient, and definitely work.