LAN Addict has posted a review on the Corepad Mouse Pad

Basically, I do not like the Corepad. I do not like any mouse pad that causes the cursor to move when I am not even touching the mouse! While the idea behind the surface of the Corepad looks good on paper, and probably works quite well with a ball-mouse, my Razer Viper had nothing but trouble, even though the Viper is listed on the Corepad Mouse Compatibility web page. I found my Viper to be far less accurate on the Corepad than on my Razer ExactMat, even when using the Speed side of the ExactMat! For what is charged for the Corepad, you can do a lot better.

Corepad Mouse Pad