Oddly enough, I was just reading a similar article from last year about Linux 3.5 bringing massive improvements to Radeon. It would be interesting to see something older like 3.2 compared to 3.12.
Dynamic Power Management (3.11) and ASPM (3.10) support itself should make a huge difference for power consumption. Add in the various performance improvements in both the kernel driver and Mesa user land the FPS should be up quite a bit. (The Phoronix benchmarks say as much as 40% improvement.)
The Radeon driver is still, despite it's faults, a way smoother experience then the fglrx driver - notably so if you want to use a compositing window manager (support still missing from AMDs proprietary end).
Yep, never ever used fglrx after radeon got usable. Allows me to upgrade kernels whenever I want and now a days it runs cool, has UVD supported and 3D/2D performance is quite decent for desktop use.
