There's at least two and probably three recent threads on the TrackIR.
I never fly without mine.
But you will hate it. Don't bother. While were talking, it would be a good idea to leave your gear down all the time, never use more than 25% fuel, and don't fly cannon-equipped aircraft (ever).
Just kidding! After a decent stick with rudder (or a stick, throttle, and rudder pedals) a TrackIR should be your next purchase.
It won't guarantee an immediate kill-death improvement, but you will have a lot more fun while you work on that.