I am disappointed that my chair with 5 double rollers distorted the mat in two weeks such that my chair would no longer roll to where I wanted it or to let me up. I didn't even have that problem on the carpet. The description here says for "Flat Pile Carpet". I've seen flatter carpet but mine is certainly not plush. And I'm not big - about 175 pounds or about 35 pounds per wheel. Not very useful for me.
Basic chair mat. Flexes a bit on medium pile carpet so it feels like your wheels get stuck in little divots. I appreciate the lack of 'spikes' on the underside but the mat moves a bit on medium pile. Overall a good product for the price.
First the BAD ... it was delivered without a box. I woke up and found the thing outside my front door unwrapped with a shipping sticker on it. It was wedged into the front of the door and the bottom of the step so I had to go out the back door around the house and unwedge it. NOT A GOOD START. The GREAT ... The mat is a fantastic size very heavy and has very spiky barbs on the bottom (careful!) so it covers the whole area and does not slide around or creep anywhere. The MEH ... Despite the map being on low pile carpet it gets little sunken craters in it when I sit in one spot too long. The cratering happened within a week. I wish it was a bit more rigid. The problem is probably the fantastic rug padding under the low pile. In any case it's not bad but it could be better. So consider your rug thickness carefully.
I am actually using it to protect an area my cat likes to dig into the carpet. The pokey things keep the mat in place perfectly and help protect the area of carpet the cat fancied without creating a tripping hazard.