I tried on Tahiti and Pitcarin cards miner versions 12.3 and 12.4. Speed is 2-3% more on 12.4, but 12.3 and 12.4 not stable neither lowing intansity not using an "-old 1" option. Different versions of drivers not stabilize 12.3 and 12.4 miners too.
Version 12.2 is the most stable version for GCN1 cards with any intansity or drivers, but slower than 12.4 version.

Claymore, would you make a new version with speed of 12.4 and stability of 12.2?