Well, I have one of the aimtraks installed in a guncon now. It took me quite a few tries to get it to calibrate, but now that it is, I am pretty happy with the accuracy. I was able to hit whatever I aimed at in Area 51, until my arms started burning, then I missed a lot.

It has been a while since I have shot for that long. I was playing without crosshairs, and the offscreen reload worked great.
When not in a game, I was watching the mouse cursor as I aimed. The cursor lags behind a little bit, but it does catch up and becomes accurate. I have the tilt/z connection set to continuous, so that may slow it down some.
I have used act labs guns and the LCD Topgun, and I can definitely say that the aimtrak beats both of them by a wide margin so far. I still have a lot of testing to do; I am testing it on my desktop. so I still need to get it working in the cab.
I soldered one of the buttons to P1, and it is not working, so I need to figure that out. The outer button on the gun is attached to aux, and it works fine.
I used guncon 1s for these, and I really like them. They look great and the aimtrak fits in there easily with only a little bit of trimming inside the barrel. Andy said that his will be similar to the guncons, so I think this will end up being a really nice light gun solution for our cabs.
I watched some of the videos in the various threads, and properly calibrated, it is accurate over the entire screen, except for the lag I mentioned.
Edit: I have been playing quite a bit tonight and having a lot of fun. I am ready to move the led bar to the cab so I can get everything set up in its new home. I have a suggestion for those who have not ordered the aimtraks yet: Buy 2 of the full kits. I have been playing sitting at my desk, and I would like to keep that option, so I really wish I would have bought the second led pcb. Shipping is too expensive to get one now, but I wish I would have thought of it before I ordered.