I agree!<br><br>For use in a survival tin, a Photon would be close to ideal. The size is miniscule, and the lithium batteries in it should have a shelf life that is far longer than alkalines.<br><br>However, for a general-use keychain light it is a much closer call. The photon has size and weight on its side. The ARC is tougher and cheaper to operate. I also do not think that a photon could survive a good dunking in water, while the ARC is waterproof up to 3 feet.<br><br>The light output from both lights is nearly the same.<br><br>