The filter will dramatically diminish the brightness of the light, but if you are using it in thicker areas, it shouldn't be that bad.
I have one myself and it worked fine and the beam is very narrow on it. But it does work great as a spotting light. The big issue I had with it was the area saturation. The lens container is clear and light bleeds through the side of the housing making it really hard to see if you are using it as a gun mounted light. There is a cap that you can get from RestoreC that has the bleed cap and the red filter lens. It seems reasonable as well.
The light and the time it runs is excellent, but I wish it had a remote momentary switch with plug option to turn it on and off at full brightness for shooting. The clicker switch that is uses is a bit hard to find and adjust when using it as your aiming.
I can't night hunt in Arkansas without Game and Fish permission, but I do make trips to Texas every year to night hunt. I am moving more toward Night vision scopes in order to still perform the hunts but keep the visible light down. So once I complete that, I will probably sell my Light-force 170 and my predator light to a new home that will use it.