I put this mat under our desk chair on carpet with a flat pile on Friday. There are already dents in the mat under the chair wheels where I sit. It has not yet broken but the dents make it harder to move the chair.
I got a medium pile mat which was terrible. Staples took the return without argument (good job) and up-sold me to the thicker 1" pile mat (special order). It came in less than 48 hours ( great). While I was waiting I checked the depth of the carpet and under padding and it was 3/4" at most so I figured the 1" deep pile mat would do the job well. Unfortunately the 1" mat still sags after sitting still for about 15 minutes. My 5 wheel office chair weighs about 25-30 pounds and I weigh 185 so I would have hoped it would be better. Every time I try to move an inch my chair rolls back into the original "holes" which is frustrating when I work 10-12 hours a day. It will do but was hoping for better.
I have my mat for my home office desk and love it. It protects my carpet from wear and tear as I roll around on the chair. no problems.....holds up quite well.....and let's me easily find and pick up anything that falls or spills onto it.....saves stains on the carpet for sure!