Do you have better performance with open source drivers? I think Firefox is equally slow with proprietary and open source drivers for me.
The Catalyst 13.8 release is still on track for release later today/early tomorrow. Though I haven't heard about anything Linux specific just yet, so fingers crossed :-)
The Linux release of Catalyst 13.8 Beta will happen within the next few hours.
From my initial testing of what I expect will be the same release as will be publically released shortly, OpenGL input lag remains problematic for certain ASICs.
Still 3.8 (or is that 3.9?)?