CPU: Core i7 GPU: GTX 280 Unity, ubuntu 12.04 I have a dual monitor set up. I can alt tab, and can use the overlay and switch between programs seamlessly. Alt-tabbing switching between programs is fast. I can actually do something on the other monitor without the game screen disappearing and having to wait for it to load up again (sometimes crash) like it did in windows when I alt-tabbed.
One minor bug, when I first opened tf2 it detected my keyboard layout (programmer's dvorak) and remapped all my keys properly in the keyboard settings for steam. But it didn't work, so I set it back to "defaults"(in steam) which is qwerty which works?? However in chat, I'm able to type in dvorak. So TF2 seems to require qwerty in the keyboard settings for steam for game input but reverts back to the system keyboard for in game chat?
This is very minor bug for people who use different keyboard maps. It's just not consistent, but it works.