Even on a flat pile office carpet this mat was too soft. Dents would form where my chair had sat even if I wasn't sitting in it at the time. I chose to exchange this for a firmer better quality and slightly larger version.
I have two chairmats so I can get from one desk to the other. I like the fact that it protects my carpet from snags and wear. I would recommend everyone use one to save wear and tear on carpeting. I am very pleased with the mat and how it holds up.