This issue was recently discussed in another topic....
http://www.quiltingboard.com/t-65541-1.htm
Personally I would only have the green Olfa cutting mats in my shop and my home studio.
They do not dull the blades.
They do self heal.
They are restorable (see posts for info)
They are were the originals; the rest are copies/knock-offs and haven't necessarily improved on the Olfas.
Jan in VA