One of the hardest gun sight to use especially with trackir. It is hard gunsight and will not compensate for head movement like say a P-47 with a reflected gunsight on glass. If you saved head position is just a little off, the sight will be off with the bullet stream. I use trackir and have thought during it off in the line up for the shot would help especially if you hit another view and let it default to a fixed head position.