Mat does what it's supposed to do...protects the floor. I only wish I bought one sooner because my daughter has scratched up my hardwood floors in her room while sitting at her desk. The only issue I do have with the mat is that is does slide pretty easily so I fix it probably everyday.
I thought this product would work on a relatively thin carpet with underlay but with even a small amount of weight the chair will constantly settle where the chair rollers meet the mat. Not workable for anything with an underlay.
I use it in my apartment so I can keep the carpet in front of my computer table in good shape. After 3 years of use the carpet was without a mark. I bought a new one for my new apartment.