I've only had the Low Pile Carpet Chair Mat Lip by Quill Brand for a few weeks but so far it works pretty well. I've had difficulty in the past with chair mats because my carpet is a bit thicker and the mats seem to crack and fall apart. We'll see if this one holds up.
This mat for under my desk chair is incredible and necessary to keep me productive at my laptop. An excellent way to help save the rug as well. I would recommend this to anyone who has a floor or floor covering which they seek to keep in good condition.