We bought 2 of these mats. They are thick and appear they'll last for a long time. These mats have nubs on the back instead of spikes to hold them in place. The one under a rocker stays in place. The one under an office chair walks just a little bit (a little nuisance but not a deal breaker).
This computer chair mat is nice. It works well under my chair and is easy to move around. It is however thinner than other mats I have purchased and therefore will very likely begin to crack sooner than I would like.
I've owned a Hard Floor Chair mat for a long time. Lately I purchased a new one and I am astonished to find out now that the mat doesn't only protect the floor but relieves muscle pressure. Distracted with work I hardly realized the muscle pressure used to stop my desk chair from slipping on a hard floor while working; what a great difference! Everyone should own one it is worth every penny.
Works okay I guess but dents very easily. therefore sliding back and forth is really not possible. Would probably work on flat carpet but I bought it since it said it was for carpet up to 3/4" thick. This carpet is not even 1/2".