Product review (4 stars): Without lab testing my water, I can only hope it is working.
I have used these every 6 months for more than a year (now on 3rd filter).  They fit fine seem to work well.  However, there is no way to know how well the filtration is unless I would have the water lab tested.  So, all I can do is hope it really filters well.  But that is true regardless which brand you buy or how much you pay for these things.