I never win anything, but still posting! Oh wait, I don't have L4D either...
EDIT: Barker_s, the falcon is for a more immersive experience, so if you tried playing a competitive multiplayer game chances are yes you would get owned because it simulates recoil, whereas a mouse doesn't.
Interesting concept. I can see it working quite well in immersing you in a singleplayer experience, until you encounter a hard spot, say "screw it" and grab your mouse In multiplayer it will put you at a disadvantage, almost like playing with a pad among people with mice.
It could work well with a console though, probably much better than a pad in FPS games.