I really like my mat--I just wish it wouldn't ruin so quickly. I had a huge hole in mine (but I think that is my fault since I have to roll around it so much all day long!). LOVE IT:)
For thick carpet needs deeper cleats. The chair wheels leave dimple marks in the surface and the wheel rolls back into the dimples so you are constantly moving the chair back into place.
Bit overpriced - thick understandably for reliability. But because it is stored at the store in a cylinder its difficult to lay out flat. And it is somewhat bumpy to roll over. We currently have it on industrial/commercial carpeting.