Does anyone have any experience with one of these? How do they compare up against a photon LED light/or similar? Is the beam stronger? I have had a couple of the photons on my keyring(s) in the past, but I have been curious about the reviews on one of these. Also, I think streamlight makes something similar...I think, anyone use one of those? If so, what do you think. I guess my main concern would be having it twist on in my back pocket with my keys, or having the top fall off, I don't know if that's even possible, just look's like it may be. Any input would be greatly appreciated. Thanks!