Depends if your used to cloth or solid surface. I personally use Razer Matis Speed, but not with a Copperhead. My best friend uses an Icemat Black 2nd Edition (glass surface) with his Copperhead and thinks its great.
Also depends on what size mat your after, the Icemat is rather small compared to my Mantis (less than half the size) if you have high sensitivity then small won't usually matter but if you use low sens then the bigger the better.