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.