It's nice they want to use the radeon state tracker, but it really needs work. Really.
HD 6550 mobile here.
The mouse pointer still has a garbled square around it. xrandr is still not properly supported (multiple screens work, but rotating does not work).
Switching from X to a tty and back is slow. Recently with xf86-video-ati-git and linux 3.4 it really got as fast as it should be.
At the moment OpenGL is completely broken it seems. Even glxgears:
Kwin OpenGL compositing just garbles the screen, xrender compositing works.
[ 308.506845] radeon 0000:02:00.0: evergreen_surface_check_1d:240 depth height 300 invalid must be aligned with 8
[ 308.506856] radeon 0000:02:00.0: evergreen_cs_track_validate_depth:653 depth invalid (0x00000027 0x000005db 0x00002022)
[ 308.506863] radeon 0000:02:00.0: evergreen_packet3_check:2055 invalid cmd stream 468