A 5 caster chair even when empty overnight leaves indents and then won't roll easily. Mat needs to be of a harder material. I have had one in the past and did not do this.
The title is a bit tongue in cheek. However I found the vinyl material to be ill-suited for my needs with my low-medium pile carpet. Because it's not a firm material my chair is constantly sinking into the vinyl and becoming stuck in these wheel sized ruts. This makes it no easier to roll than when I was not using the chair mat. I can't recommend this for anyone who isn't using a low-pile carpet material.
The mat does what it is designed to do. Vinyl is thick enough to protect carpet from chair rollers wear marks and tearing of carpet. Has vinyl studs on the back of the mat which hold the mat in place where you lay it. I am please with the mat and design. The only complaint I have is the store had the display of these mats rolled up with clear packing tape. After getting the mat home I had to use "Goo Gone" which is a adhesive remover to get rid of the tape residue off the mat. Which took it all off with some effort on my part. I understand why they were rolled up for easy Cash N Carry but string or twine would be better as it would leave no sticky residue on the mat.