I have, IMO, one of the sharpest and most honest A/C guys I know. He told me that the only thing the 3M filters do is restrict airflow. He suggested getting the least expensive air filters you can buy and change them frequently. You'll save money not only because your system won't have to work as hard, but the filters themselves will be much cheaper. And the difference in allergens will be negligible.
I get a bulk pack of filters and change them every 4 months.
Here's another suggestion...and don't laugh...I bought a Roomba. My daughter has one and she loves it. So I bought one (not the most expensive one, you don't need all those bells and whistles) and I run it every other day. You should see the amount of hair and dust this thing picks up! I have a dog that sheds a lot and lots of trees and flowers on my lot and have had zero allergy issues.
