Re: Surefire KL1/E2E vs ARC LSH-P
The Arc AAA doesn't try to be a real bright light; it's about like a typical LED keychain light in brightness. I'd say it's more than a keyhole finder. It's fine for walking in the dark, for reading, looking at maps, or most other close-up tasks. It's not a searchlight. The difference between the Arc and (say) a Photon is that the Photon light will be bright for the first few minutes with new batteries, then taper off into uselessness and then you have some semi-expensive lithium coin cells to replace. The Arc will run with near-steady output for 4 hours or so on a normal easy-to-find AAA before dropping to "moon mode". Then if you give the battery a rest it will run for a couple more hours with near-normal brightness. If you have an AAA-incandescent light like a PT Rage, after the Rage's batteries are too weak to run the Rage, they're still good for quite a while in the Arc, because of the Arc's built-in dc-dc converter.
The Arc is also made of hard-anodized aluminum instead of plastic, and doesn't give the impression it will flake out like the squeeze lights, though I haven't had mine long enough to know what will happen. It has a 10 year warranty in case something does happen.
The Arc AAA LE/PE is the same as the regular AAA except the LED is specially selected for neutral color. It's a lot more expensive than the regular AAA. I think the regular AAA is a better value ($17 at Countycomm except now out of stock). I have the regular AAA, whose light has a slight blue cast and it doesn't bother me at all.