The mat definitely stays in place but because the it's relatively thin and fairly flexible my desk chair still forms divots. The carpet we've got is semi-low pile but not very low so that probably doesn't help. I'm going to have to get a thicker mat.
It came (delivered) quickly & in pristine shape. I ordered one for a low pile carpet but it is hard to roll after sitting in one position even for a short period of time. The mat tends to give under the weight of the wheels on my office chair and I have to roll the wheels into an alternate place on the mat in order to move around. It doesn't mark up from rolling over it but the indentations make the rating lower than I had hoped. BTW I am under 170LBS so my weight shouldn't have been a factor.