Let's have a look at Catalyst 13.01's performance versus the Catalyst that 12.10 installs (Catalyst 12.10). I'll even take a peek at the latest Catalyst 13.02 Beta 3 to get an idea of things to come.
HD 7750 running Unigine tests
Unigine Sanctuary shows no changes but both Unigine Heaven and Tropics sees improvements in the latest Catalyst release. The beta drivers shows a performance regression in Unigine Heaven, though. Since it's still in beta there's still hope for performance to return to current levels.
Take into account the recent latency improvements AMD is making to their drivers, particularly for GCN-based hardware, it seems there's still much more improvements possible here.