I live in an older home, and in a hot and humid state. I own 2 boxers, 1 cat, a husband and have my 1 yr old twin grand babies 3 days a week. I'm also 64, with the nose of a "bloodhound" (per my family).
I tried these a while back, and I love them. They keep the guess work out of filters, as I found myself changing them often, because they "looked" ready. With the color change of these filters, I find I change them less, and I absolutely don't have any noticeable smell... so "bloodhound" app...