I used my Big Dragon Tracer unit for the first time during an all-night game held this past weekend, and the unit performed flawlessly. It appeared to sense every single BB that was fired, and lit it up very brightly.
The guys I was shooting at ommented that they could see the light going off in the unit, which made it look like muzzle flashes in the darkness.
Overall, I'm 100% delighted with the purchase.