I installed the driver on my Asus 1215b which has one of the lower end Fusion chips in it that sports a Radeon 6310. It is MUCH smoother running this driver. Scrolling in Chrome is fluid and, as was said earlier in the thread, it seems overall 2D rendering is much better as the whole desktop seems more fluid. XVBA works in XBMC for video decoding and suspend has been working since I installed the 12.9 embedded driver.
I hope this is an indicator of where things are going with the driver. My only concern is I see that the early release driver in Quantal is being reported as very slow. Hopefully, they get that sorted out before the final release.
legluondune, what DE are you using? Is it Unity by any chance? Compiz 0.9.8 introduced a few new options in the OpenGL plugin, namely "Framebuffer object", "Vertex buffer object" and "Always use buffer swapping", which, in my experience, made moving windows around feel slow and sluggish and caused somewhat higher CPU usage. So I disabled said options (as well as Sync To VBlank and enabled the Tear-Free option in CCC) and my desktop feels snappy again.
I have just installed the driver in Ubuntu 12.04 (64-bit) and it works fine! This time I tried the "generate packages" method, which should make it easier to uninstall/upgrade. Beware though that the installer requires some dependencies to be preinstalled. Here is my recipe (for 64-bit version!):
# Run installer
sudo sh amd-driver-installer-12-9-beta-x86.x86_64.run
# Select "Generate Distribution Specific Driver Package"
# Select "Build package for detected OS: Ubuntu/precise"
# Installer should now run to completion without errors
yes, fglrx drivers are now avalaible for quantal, but with poor performance compared to same config with precise
Finally I have good performance with this drivers. But with Unity, wine games wich need big ressources (AION, Skyrim) have a poor framerate, it's unplayable. Anyway, I launch them on metacity and that's ok.