I just brought the Track IR4 last week, and it is my very first TrackIR device, for months, I had hard time to decide if I should buy one or not, and I fanally brought it.
Dude, BUY it, I felt it is a whole new flight simulator to me, ability to keep eye on bandits, watch out hills just for merely 1 seconds while dog fight in low altitude fighting, keeping eye on ground target while bombing, zooming in to do cannon shooting on targets, and so much to discover :)
It is worth the $ for TIR4.