Understandably this is all purely anecdotal, but installing fglrx using smxi on Crunchbang 11 was actually a relatively painless experience. My gaming machine

Understandably this is all purely anecdotal, but installing fglrx using smxi on Crunchbang 11 was actually a relatively painless experience. My gaming machine has always been in "Windows only" territory due to the fact that I tend to run configurations that are slightly outlying -- my current machine has three monitors and two AMD 6970 videocards, with two monitors attached to one videocard, one attached to the other. I was incredibly surprised to find that this configuration worked 'out of the box' on #!, and continued to work perfectly after the install of fglrx drivers. No issues with hardware acceleration, no crashes, no difficulties whatsoever (beyond having to increase the 'virtual' resoluting in xorg.conf so I could move screens where I wanted in xrandr.) All this brings me in a roundabout way to my point: If my wacky configuration can work relatively seamlessly in an arbitrary distro, I tend to think that AMD will probably be able to manage to get fully supported configurations running on SteamOS in a straightforward fashion.