I'm not very heavy (170lbs.) and my office chair has five casters so the weight is well distributed. However the chair still sinks into the surface when used on a medium pile rug making movement difficult.
Scuffs easily and the rollers from the chairs leave dents and ruts. Also we have had them about a week and all 4 of the mats hasn't totally laid flat yet. Will not purchase this brand and style again.