Good light but… - Crimson Trace Cree XPL LED Waterproof Tactical Weapon Light

So I have 3 of these lights. One stays on a 16” AR15 and works to perfection. The mount doesn’t come loose from recoil and it works every time I need it to. Another one is in a drawer in my nightstand and works well for needing a flashlight circumstances. The third one sucks. It doesn’t stay on the weapon it’s mounted on and constantly comes loose. I need to change its battery almost every time I use it for it to work. I took it off and it stays in my safe on the shelf. I guess as a back up light/parts. I took a tactical course and the light stopped working half way through the class. Yes a new battery was installed before the class. I guess 2 outta 3 isn’t so bad but as with everything, you get what you pay for. Get yourself a stream light. They work great all the time every time for the price. If you want to go high end, of course get a Surefire.