You are right about the Photon Lithium coin batteries tkl, they can be found easily and probably last longer and are easier to carry, but try changing them in the dark or low light without losing the screws on the II's and the thin little cap on the III's, not to mention having to have a screwdriver in the first place. Speaking of which I bought a great little Husky electronics screwdriver with reversable hex bits that store in the handle for $6 today at Home Cheapo very compact and great for glasses electronics and Photons. Photons aren't waterproof either.
Well, I just tested again. Photons II and III same level of brightness with similar hotspots. Both LE's are slightly brighter than Photons in the hotspot and significantly brighter and more defined flood in the halo (due to reflective recess). The main thing is older LE (slightly off center with protruding LED) has broader flood and tighter hotspot than the new LE (or Premium, slightly more recessed LED) it has a slightly broader hotspot with a slight ring and tighter but well shaped and just slightly brighter flood area. Wish I could show you pictures,and I wish QC was more consistent on the AAA's
In my opinion the Arc LE is just a little brighter but emits more usable light (due to the reflective cone) than the Photon. I really do love my AAA LE's.
Later,
TSG /ubbthreads/images/graemlins/grin.gif