Just arrived today!  Chair rolls easily on my somewhat thick pile carpeting.  I have not spent hours sitting in my chair, but so far it appears to not make indentations and does not shift around.  Lightweight and the spikes underneath are rounded so less "lethal" than some other mats I have used in the past.  Happy with it!  Use it next to my art table should paint brushes fall to the floor (to protect the carpet.).