I've been using this desk chair mat for 2 weeks on medium pile carpet. My 5-wheel desk chair does leave divots while I'm working/sitting in the chair. So far the divots are not persistent; they level out in a few hours. I have not found the divots to be a significant issue as others have commented. If you want no divots using a desk chair mat on medium pile carpet one option is to spend 5x on a glass chair mat. For the price I think this vinyl mat works well.
The product itself is just fine but the process of getting my delivery was horrendous. The first delivery was lost no one had any idea where it was. When the reshipment arrived one of the products was damaged. Eventually the correct order arrived but not after countless chats and phone calls to get this resolved.
The pad is OK but I thought it would be stronger. I have a 100 lb. bird cage on it and the wheels made impressions in little time. A person in a chair would be twice the weight. And it was delivered by Ontrac sort of rolled up and taped. I spent 1/2 an hour using GooGone to get the tape residue off of it. It works for what I wanted and cleaned up fine.