Others experience re: subs and Magmepan 20

I have a pair of Magnepan 20r’s. Have enjoyed them for years. In my room they go to about 30Hz, response way down at 25Hz.

I am experimenting with a pair of Janis subs. This gets the response to about 25 Hz then down a lot at at 20Hz. It adds a little something but not I am not bowled. over. I hear and feel a bit (in my chest) on some music.

I would like to hear about others have experience with adding subs to nearly full range speakers?

Did you feel you got your money’s worth for "a few silly Hz"?

Thanks