I've had this item in my house for a week. It still has bumps that have not flattened. I also have it on carpet. The little teeth on the bottom do not stay in the carpet. My chair is on wheels and I've had to move the mat every 2 days to put it back in place. Because it moves the chair wheels get stuck if I move forward too much I can't get the chair to roll back.
It’s not as thick as I expected so with how plush my carpet is my chair doesn’t roll as easily. BUT it’s better than being stuck in the carpet and not able to move. I’m satisfied.