Well, I will post this because it may help some of you who also had a bad experience with those drivers.
Rig is in the signature and in the "System Specs" to the left too.
My first contact with "Crimson" was not utterly catastrophic, since my computer still booted after installation, but pretty bad since I lost 1000 (yes!) points in 3DMark11 and over 10 fps at exactly the same spot in World of Warcraft.
I had installed them over the previous drivers (Catalyst 15.11.1 beta) like I always do.
I then tried several things, like completely uninstalling the driver and reverting to the 15.11.1 and even the 15.7 WHQL... and dang, this time I was getting pissed, because I wasn't getting my performance back. Even with older drivers, my WoW framerates remained pathetic and my 3DMark scores even more. Also, when I went back to the Crimson drivers, the new control panel was regularly crashing and unable to be accessed unless I reboot.
At that point I was about to give up, and was even starting to think about reinstalling Windows to get my original performance back.
I went for dinner, took a welcome break, and when I came back, I tried a "last ditch" thing and downloaded "Display Driver Uninstaller". I wiped the whole thing, rebooted to a nice (=P) 800x600 VGA desktop, and installed the Crimson drivers from scratch.
And there the magic worked. Performance in WoW was back to normal and more. I gained performance in 3DMark11 and 3DMark too. The settings APP is working. My system is nice and smooth again, with improved performance and the nice "shader cache" which reduces my loading times.
So guys, if you had a bad experience with those drivers, I recommend doing and complete driver cleaning before reinstalling them. It's definitely worth a try.