Is Arc LE any brighter than the Arc 3.1?

Is the Arc AAA LE any brighter than the Arc 3.1?

That'll depend on which LE and which 3.1. The LED's themselves vary enough in brightness to give one sample the edge over another. A V3.1 LE and a V3.1 AAA should be quite close in brightness. Really, the main difference is the tint of the S-ranked LED.

The LE first came out long ago, and my guess is that 3.1's in general would be a tad brighter. But I've been wrong before.

My LE and my 3.1's are about the same brightness. Too close to call, and the difference in tint makes the comparison all but impossible with the naked eye.

If they're so close in brightness, what makes the LE cost $10-$15 more? Is it simply because its "limited" and grey HA rather than black HA?

yup

The SB1 LEDs are apparently harder to come by.

One or two more questions: Do the threads, which are bare aluminum, show appreciable wear with use? In other words, do you notice more slack in the head-to-body fit? Who is selling the
black HA, 3.1v at the best price?