This is a great filter. You can really feel the difference with the water quality. The only drawback is that it does affect your water pressure negatively after a few months and after about 6-8 months for me, I have to change it because the pressure gets so low.
Very happy with the AP817 filter. With just my wife and myself in the house, the filter lasts for a year with no change in water flow, taste, or odor. (Our last AP817 lasted longer, because we were traveling for about 90 days.)