Works fine in openGL applications, and after sorting out some issues bellow, works with only a little tearing on windows and expo in Cinnamon
Once the proprietary drivers are installed, GRUB works beautifuly, in all it's 1080p background goodness :)
|What doesn't work:|
As of September 2014:
On install of Linux Mint 17v2 Cinnamon edition, you have to boot in safe mode on most boots, inc install, this issue is fixed by booting in safe mode and installing the proprietary driver from the driver manager.
DO NOT install the driver from the AMD side as it doesn't currently provide any advantages, and you cannot uninstall it without without major issues with xserver.
Tearing, lots of it, all over Cinnamon. probably xserver polling millions of un-needed info between the client and server, but it would be nice if there was a way to fix this.
|What was done to make it work:|
Booted in safe mode and installed the proprietary driver from the driver manager.
As of Linux Mint 17.2 (July 2015), everything above is fixed aside from the tearing, which can be fixed by enabling tearfree in the catalyst, just be sure to turn that and vsync off if you plan on opening a game.