It might seem strange for me to answer this but I am going to try to be as honest as possible.
A few years ago I started looking at lightgun options, but stopped all work when the Guncon drivers came out. The reason I re-started work on this was virtually nobody seemed to be getting good results with the Guncon on a PC. Now I might be wrong about this, and please feel free to correct me on the above.
The AimTrak offers fast response, easy usage, no drivers nor software, and useable close to the screen.
Its extremely accurate following calibration, and will be even more so when I make some changes.
It has a limitation in that it must be used at the same height and screen distance as it was calibrated at.
There will be enhancements to the calibration process. At the moment I am working through the comments on the config utility, starting with tidying up the firmware upgrade process, which is now done, but other issues to look at. Then I will improve the calibration. But, the limitation on moving firing location after calibration will always remain. Its that limitation which is causing the doubt in the comments on the forum. Whether or not this is an issue depends on your method of playing so it introduces some subjectivity.
In the original design phase I assumed that the gun would be generally used at eye level when wanting to aim without crosshairs, thus the same height, and that the user would generally be a similar distance from the screen, as arcade guns are constrained in distance. So I considered the design viable. Whether or not I am right is open to debate, and has been on this forum.
Andy