I've only used the mat for two weeks so I cannot comment regarding longevity. The mat doesn't slip on my berber carpet. My chair glides easily on it. It flattened out fairly quickly. It's met my expectations.
Chair mat was delivered to my home- nice & easy. Unrolled slowly over couple hours. Has nice smooth edges if chair needs to roll off edges. But I gave it 3 stars because once down and in use it travels side ways. So I have to remove the chair pick up the mat and re-place it on the carpet where it once was. Maybe my previous mat had different "grippers" underneath. This one is not that good on the carpet height that it was recommended for.