I promised more. Here it is...some of my personal experience. Bear in mind that I use Track IR3 Pro with the Vector clip and I'm not a regular frequenter of the TIR forum (haven't been there in ages, in fact), so some of this may have been overcome with TIR4.
One of the problems that have been encountered with Track IR, particularly the Vector clip, is that the reflectors sometimes aren't up to the task. They curve slightly side to side to accomodate the different angles offered to the camera as the user turns his/her head, but they do not at all up and down. This leads to occassionally having it lock in the straight up or straight down view requiring a reset, not what you want to have to do in the middle of a dogfight or maneuvering close to the ground. Another is that eyeglasses can interfere with the operation by reflecting enough of the signal to confuse the device (kind of like chaff). What I've done to overcome these is both simple and inexpensive. In fact the whole thing can cost less than five dollars and take less than an hour. (I apologize for the pictures' being out of focus. Not much of a shutterbug.)
First you need to get some small styrofoam balls.
These can be picked up at hobby or craft stores or even in the craft section of many department stores. I used 1 1/2 inch diameter and wouldn't recommend going any smaller. You could go larger if you like, but I doubt it would be necessary.
Next, cut three if them into discs about 3/8 to 1/2 inch thick.
Be sure to cut them out of the center of the ball, not near the ends.
Then cut strips of reflective tape (available in many locations...I got mine in the local WalMart automotive department) as wide as the thickness of the discs and long enough to go about 1/4 to 1/3 of the way around them.
Apply the strips to the discs.
The reflective tape is adhesive-backed, but it won't stick well to the styrofoam for very long. The dark dots on either side of the tape are straight pins I've stuck through to help hold the tape in place.
Press the discs down onto the reflectors on the Vector clip.
The metal will slide right into the styrofoam with no problem
and without damaging the original reflective material. If you don't wiggle it as you put it on it will hold tightly enough without any glue or tape. I've been using this for well over a year now, and I haven't had to replace a single disc or had it come apart in the middle of a game.
The effect is dramatic. The image your unit sees is about four times as large as the standard clip and with a vertical curve as well as a greater arc on the horizontal curve they stay nearly that large until you're looking well past the edges of your monitor (unless you're using a 60" tv as your monitor...then you're on your own
). This maintains a solid 'contact' with the unit, all but eliminating the dreaded "stare at the chair" (only time I get that now is when I have to look down at my keyboard for something)
and allows you to decrease the sensitivity which reduces the interference.