I've tried it in several 6V lights and like it very much. It was an improvement to all the lights I tried it in. Somehow the side-emitting Luxeon produces much less artifacts than the incans that are replaced. I just recently tried it in a new Dorcy light I was testing (Xenon Palm Lantern) and the result was a nice white focused beam with little artifacts. I cannot comment on it in a Mag because I don't have a 4-cell Mag but I tried the LPR-3 (4.5V) in my 3D Mag and was very impressed. I re-read the review on Doug's site and concluded that either he had a bad one or they changed the bulb, as mine put out just a little bit less light than the Mag 4.5V Xenon (!) incan. The package of mine is different from the one on Doug's site, so maybe they really changed the bulb.