I didn't notice a difference in BFS and CFS, but I was using different DEs at the time, and the DE has 10x more effect than the scheduler. I felt the same way with regular kernel vs low latency kernel. In other words, no changes are noticeable unless you run Openbox with no desktop environment, because desktop environment implementation is garbage in Linux. The cursor also feels like it's operating with lower granularity than Windows for some reason.
Another issue is that if you change system settings while using gnome, then boot to openbox instead, settings such as xinput, and others, will all change or revert back to default. Even the soundcard seems to change settings at random, so your sound may or may not still function. This means if SteamOS takes off, but they give you non-optimal factory settings, changing to gnome desktop to try and change the underlying OS, then going back to Steam will only work for some things and not others.
I'm done with Linux for now. It does everything the opposite of how things should be. Things that should be compartmentalized and function regardless of how you set up the system aren't, such as specific apps being locked to desktop environments, and things that shouldn't be compartmentalized are, such as even some Nvidia control panel settings only affecting one desktop environment and not being a system setting.
The only way Linux can be functional is if it comes out with a standardized, efficient, hardware accelerated desktop, that can then be skinned or modded to create the looks people want. Right now it's just a giant herd of people mindlessly wasting their time all working on different desktops that have no future. I don't see SteamOS being useful at all unless they fork away from all upstream changes like OSX, which means it might be a decent gaming system 1.5-2 years from now if they decided to do that today.
Made a post about Linux in the mouse section too: http://www.overclock.net/t/1548204/linux-the-clown-os