I have used these filters for some time and I wouldn't dream of using anything else. They really do their job. I am impressed and a little surprised to see how much stuff they have filtered out when I change them and I do change them on a regular basis. I have my HVAC unit checked every six months and they bring their skimpy filters to install. You can definitely tell the difference in the quality of the two filters when you compare them. I tell the service guys don't bother I'll stick with my Filtrete filter.