I'm testing 3 miners
1. GPU: Use the modified CGMiner found here: https://github.com/eCoinSource/eCoin_GPU_Miner
2. CGminer keccak for Copperlark https://github.com/Eropi4/cgminer_keccak/releases/download/3.6.6-keccak/cgminer_366_keccak_win32.zip
3. Special reaper for SHA3 (Copperlark) http://sourceforge.net/projects/copperlarkreaper/

Miners 1 and 2 gives me 145 mh/s on my radeon 7950 with I 13, but video driver always crashing and temp. was always at 68-70. Reaper for sha 3 gives me 138-140 mh/s with I 19, but no crashing at all and temperature 62-64. So i think reaper is more better for SHA3 than cgminer keccak. IMHO