Have used these for years. With a house in a dusty area, smokers, and 2 dogs...well I need all the help I can get and Filtrete does work. Be sure and monitor the filters during times when the systems fan runs a lot to be sure you don't get the filters too loaded with crud.
We've used these air filters for years and will not use anything else. They trap so much dust & clean the air in our home it's amazing. We live where the dust & dirt blows most of the year and we have a dog that sheds so we have to change the filter about once every 4 to 6 weeks. I can tell when it's time because dust will start to collect on furniture the day after I dust.