We have been using Filtrete Allergen Defense filters for quite a few years. At first we noticed a big difference in the amount of dust accumulating in the house. Now I expect it and if we don't change the filter on time I notice more dust around the house.
I've been using these filters for two furnaces since 1989 without any difficulty. They do an excellent job of cleaning the air as I had tried other brands on several occasions because they were (and didn't turn out to be) a better deal. What is meant by didn't turn out was that dusting was more often needed when they were in use. I have made Filtrete the only air filter that I use!!!!!!!!
I have been using Filtrete allergen defense for 6 years, and can honestly say that my allergies have improved due to the air filtration it provides. Inhave tried other filters, but tis on definitely cuts the dust and allergens in the air by a measurable degree. It is very well-made and is definitely the best on the market -- and my HVAC guy also approves!