Track IR has its own issues with lighting. Too much light which interferes with the IR receiver can cause the setup to be dysfunctional. Its the best in 6 degrees of motion tracking for now for sure but not an ideal solution without its downsides either.
I found it very reliable over the years. The TrackIR tool has a slider that allows you to change the sensitivity of the camera. The only issues I ever had was at work when a camera team put up those bright camera lights. But even then the slider helped. It is also easy to check because you can actually display what the TrackIR camera sees.