UPDATE - PLEASE READ: Following some comments suggesting that the vibration on the 3M could be due to the pad saver, I have responded to this via an Instagram story here : https://www.instagram.com/stories/ragnbonebrown/3151964799280130289/
Here are some links to my previous videos about the Mirka DEROS:
When my Mirka DEROS sander broke (Jan 2020) https://youtu.be/WNPD_6-Gdmw