I've only been using it for a few days but my only complaint is that it is easily warped. I have it on carpet and it's perfect to keep my desk chair mobile. But if I sit in one spot for too long it sinks and makes it hard to move.
This chair mat is pretty good quality for the $$. I haven't had it very long but it does have a wee bit of indentation where the chair rollers sit on it. I loved the delivery though it was delivered flat not rolled up!!
I bought this mat to use on a carpeted floor. The chair wheels leave dents in the mat after sitting in one location for a while. Makes it hard to move around.