few notes, its still in beta, so yes there are bugs...its optional so if you don't want to use it, just like win8, don't use it
i used it a lot last night, it makes gaming in the living room much better. its no perfect, some games launch a settings window before you get into the game, so you still need a mouse (i'm looking at your trine and trails 2)
but overall, its very nice, you hit the xbox button on the controller and it does the same as ctrl tab or alt tab...access big picture and search the web, chat with friends (typing with a controller is much improved over any other options), or just launch a different game...
i love pc gaming, been playing since the 386dx days, and i don't mind changing settings or dealing with keyboard and mice, when i'm at my desk...
but for living room and i don't want the added clutter of a keyboard and quick play games, this is a huge step forward, really if they added live tv and netflix/local media then i could forget about media center/xbmc and just leave steam running, its simple enough that my wife would like using it (she thought it was my xbox and was impressed it was the pc)
i just hope they can get dev's to patch some games to make them more Big Picture friendly and they are set for me