Hey mate, Just got track ir4.
Picked it for 150$ on eBay, absolutely amazing can I say!
I would really recommend any of the track ir systems. The newest is track ir5, as I didnt have the money I decided to go with trackir4. I downloaded a profile of the web and configured it to what I wanted. Works perfect with the A10C, Hawk and Mig21bis so far.
Would 100% recommend!
Regards, MrChickies