The only good thing about Trackir is the device itself, the hardware working well. Though i'm still not sure that 4 IR LEDs pointing directly into my eyes do not pose any harm. Well, i just don't like the idea of lighting that way, whether it's visible or invisible IR light.
Anyway, everything else about Trackir is disappointing. First of all, the software. From the very start of Trackir 1 appearance, i saw many people puzzled to see it using its own closed interface instead of standard Windows Directinput. That's not bad by itself, but that did look strange, for there had to be some unexplained reason about it.
The years have passed, and now we face the situation when we just can't use old Trackir with modern games like DCS, because new games work only with the new TIR software, but it doesn't support TIR 1 and 2. So, if you bought your TIR, you're not guaranteed to be allowed to use it with new games in the future, as it happened with TIR 1 & 2 users.
That's the beauty of a closed interface.
For those not satisfied with the standard TIR software abilities, there were 3rd party programs, acting as middleware, FreeTrack for example. By using it, TIR 1 user can play a modern game, if he changes view controls in the game to a standard DirectInput device. But well, "Natural Point™ requested us to remove Track-IR™ cameras support from FreeTrack." Oops.
Reasons? Consider yourself.
"Concurrent access to the TrackIR data for multiple games at a time was never part of the official specification. Some applications were utilizing this (when they should not have been), which caused them to break when we updated the TrackIR interface to conform more closely with the specification."
Moving further, TIR software functionality is very basic. Just play with the response curves. And if you're not satisfied with it, it's just not for you then.
Sometimes people feel unconfortable or even sick when using it. Such a case requires different, more advanced control algorythms. But what if you'd like to implement your own algorythms? Look at the paragraph above.
The situation is quite adequate for the point'n'shoot community, but it just goes against the tradition of advanced input hardware utilization, which is usual among the simmer community.
Turning back to the hardware question. TIR 4 showed to be prone to overheating, because of deficiency in LED power supply design. At some point the situation became obvious, as many people were complaining about this. What happened next? We were presented a new device, TrackClipPro™. Three LEDs on a wire frame for just 34.95$. What it gives you? You don't need to wear a hat anymore. And also (it isn't mentioned there), LEDs in Trackir stop lighting, thus it doesn't heat. I personally liked that move.
Resuming, Trackir is a good piece of hardware, it almost has no alternatives. But i strongly dislike the marketing politic which NaturalPoint has been promoting through all the years. It continuosly hinders people's efforts of using Trackir the way they want it, not the way they're bent.
I hope NaturalPoint guys will read it and think about it once more.