I've got the Longbow Micra. I also have a SureFire E1e and Arc4+. I use my lights mostly for work. I'm an electrical engineer and do tons of reverse engineering and failure analysis. So I use a portable microscope--the light is used for illumination of the subject. I also do lots of camping and backpacking so my lights get pressed into double duty.
So here's how they stack up:
SureFire E1e - Old technology but... Great size and feel in the hand. It's... sort of... inexpensive. It's got good throw and weak spill. It's about the right intensity for 30X magnification, six inches from the target. Summary, so so in the woods, good in the lab.
Arc4+ - Good throw, bright spill. About a 60 degree spill beam. Super with the microscope especially at lower brightness settings. Very versatile. Can get within 5 inches of the target without getting de-focused(donut pattern). In the woods and around camp, the 60 degrees of spill leaves your peripheral vision in the dark. But it has great throw and bright spill. If you need to light anything up to 50 or 60 feet away, it's great. Summary--fantastic in the lab and pretty good in the woods.
Longbow Micra - Pretty bright. Sometimes too bright for close work with my pocket microscope. In the woods however... While not as bright as the Arc4 (high setting), it's close. But the beam... WOW!!! In the woods and around camp, that beam is fantastic. Much better than the KL1 with its NX05 optic (threw the KL1 in from left field but didn't evaluate it here, sorry). And I don't mean lumen wise, I mean the LongBow with the Carclo optics is just a great beam! It's got maybe 170 degrees of spill that gets smoothly brighter till you get to the spot beam. It's perfect for walking around and getting super peripheral vision.
Summary--In the lab, so so. In the woods, fantastic!
Executive Summary:
In the lab, Arc4 wins
In the woods, Longbow wins
In the pocket, SureFire wins
All around, Jack of all trades... Arc4+, but for the money, the Longbow has to be the best value out there today!