It work best when you need a third controller like for a flight sim. (right hand joystick , left on the keyboard/throttle then TrackIr to move your view) I found FPS are often too fast pace to bother with TrackIR. (there is one on the PC) Racing is ok but not necessary.
I would highly recommend heading tracking for flight combat sims like IL2 but I doubt there will be a flight sim coming out for the Wii or any console.