It works okay on my berber carpet. My chair had already made indents into the carpet so with the mat on top my chair tends to roll to where the indents were.
Arrived quickly and not rolled up (a problem found from buying through other sources). However after only using for 1 week depressions are already forming in the mat that limits the movement of the wheels on my chair. I’m a small person (about 115 lbs.) so weight is not the issue. My carpet is a low pile berber so according to specifications on website it should be the appropriate mat.