It feels awkward while playing. I tested it in Left 4 Dead, and got a little confused. But, it is a little useful for some games. I'm going to keep testing, this is interesting.....
Last night I found out that to use it to play the older source games, I have to mess with the .cfg files. I tried it, but I wasn't entirely sure how to set up the controls. I had it working for Half Life 2, but the Primary and Secondary Attack buttons weren't bound, so I got a bit confused. It works really good with Left 4 Dead. I just have to switch to keyboard to communicate.