I have tried several air filter for my heating/cooling system but there are no comparisons to the Filtrete "best" filter ! I have persoanlly recommended it to several neighbors and relatives and the ones that switched have told me how much cleaner their homes stay now and how much better the air is in their homes. The remark that stands out the most is how "dirty the filter is when they change it. No one has seen that dirt from the inferior filters. Way to go 3M Filtrete, keep up the good work and keep those filters coming !!!!!!! THANKS