Product review (5 stars): Huge difference immediately!
This product is as good as everyone says it is.  Instant results. We've only had it installed for 3 weeks, so the jury is still out on how long the filter will last before it needs to be replaced.  I was really frustrated with how chalky my dishes were looking, so this was a perfect solution for us.

The only drawback is that it doesn't come with a mounting bracket. We were able to find one that worked at Lowes.