I'm using it on berber carpet in my office. It works as expected. It's a little on the thin side - impressions are left by my chair if I sit for an extended period of time but they come out when the chair is moved.
Moves around and already has divots in it after a week. Not sure I would buy again. I can say that I bought this on-line and it came the next day which was fantastic.
The size and clearness was perfect for my needs but unfortunately the lack of rigidness of the plastic was not as I had expected. The wheels of the chairs do make a temporary indention in the mat which then makes an indention in the carpet below which was what I was trying to avoid. Best use wood probably be on a solid floor even though my carpet is lowest commercial pile.