This specific issue has only appeared to that extent in Mass Effect and Mass Effect 2, and a somewhat lesser extent in Mass Effect 3. Sometimes there's environment texture flickering, but flickering on character textures is more common I get some issues in Batman: Arkham City, though it manifests different (blocky black texture corruption, mainly on characters' faces). I think it might have to do with how the drivers render Unreal Engine 3 games; I heard there was some artifacting in Duke Nukem Forever, which is also based on UE3.
Edit: I uninstalled the Catalyst Install Manager through Programs and Features, uninstalled the VGA drivers through Device Manager, rebooted into Safe Mode (which btw is sort of annoying in Win8; you have to go into MSConfig before you reboot rather than simply hitting F8 as the PC POSTs) and ran DriverSweeper, then rebooted back into normal operation to reinstall 13.2 Beta 3. About as clean an install as one can get short of formatting the drive and reinstalling Windows altogether, but I still got texture flickering.