Every chair pad I've owned has eventually cracked. Their real value is measured by the length of time till cracking. Since I've had this one for only a very short time it's really too early to tell if it will produce the value I hope it will.
I bought one to try (need two or three). It's perfect. The price is about half of what you will find on other sites. Says something about their markup!
Definitely not for most house carpets. The Mat is to thin and soft which allows the chair wheels to sink. I would recommend this only for a office grade carpet or a short berber style carpet.