My Martin Logan Descent Sub is a MONSTER. It produces very good, fast, tight bass and really fills my HT. Very Very impressed! But when I purchased my theater seats, each (6) came with a butt shaker. I am completely satisfied with the sound & feel of my theater and kind'a hesitant to installed them.

Does anyone have experience with butt shakers?

Pros/Cons?
Do's and don't s?
Waist of time?
Hate them?
Love them?