New miner doe seem to have lowered the temp a bit but... I have lost probably .5% to 1% hashrate at max settings...
Clocking my 7950 at 1200 and 1800 with +20 nets just under 190MH/s. Previously it was steady at 197MH/s or better with the python implementation.
BUT... I would gladly trade that for NOT HAVING TO MANUALLY RENAME AND CHANGE AMDOCL.DLL EVERY TIME I WANT TO MINE SKC!!!!!!!!!
In other words... this worked perfectly on Win 7 64 GCN drivers. Boom goes da dynamite!
You can simply replace skein.cl file with the one from previous version if it works for you better. As I am not sure what exactly slows it down on GCN (and if it depends on Catalyst version and how exactly if it does), I would rather not implement any dynamic code selection for specific cards in the miner itself.