I have both the SL6 and the Surge and have been meaning to post a full review...In the meantime, here are some observations. First, the method... I started with fresh Duracell ultras (dated like 2008) in both lights; the Surge had 3 hours on the bulb, the SL6 was new. (Both from Brightguy, both with clean, no wholed beams).
I have access to a walled-in yard 100 ft. x 300 ft. with trees and some shrubbery around the perimeter. There are some trees in the middle as well. When looking at the beam as it leaves the light, the Surge starts out as a 1" tube, then flairs broadly after about 4'. The SL6 starts as a 1" "tube" of light that looks like a light sabre out to about 15'-20'. The SL6 also has a broad ring that is dimmer than the PT, but so bright that nighttime walking in bad terrain is no problem at all. At about 50 ft., shined against a wall, both lights have almost the same hotspot, in diam. and brightness.
At 150 ft, the surge lights up everything in its path with a 25-35 ft. spread: the SL6 has a much tighter spot (like about 3-4'), but b/c of its brightness illuminates out to the side almost as much as the surge. At 250'-300', the Surge illuminates the back fence line to the point where you can identify the bushes against the fence. Without the Surge , it is complete darkness. The SL6 at the same distance can focus on the same shrub, create shadow behind it and illuminate to the side about 10' on each side of the hot spot.
These two lights, at least the versions I have, really duplicate function until about 150'. I use the surge and recommend it when you want to light up everything in front of you out to about 125-150'. At this distance, the Surge still has enough oomph to penetrate bushes and light up things behind the bushes. The SL6 is the light I use to see a more narrow perspective out to about 300'.
I used the SL6 to spot a leaking gutter during a rain storm..it was so bright, and narrow, I could actually distinguish the varying rates of the water droplets. The Surge did the same, but not at the same distance. I must say, it is rewarding to hold the SL6 at shoulder level and spot 300' away with nice white light. Recently, I escorted an elderly neighbor to her home where her ex-con son sometimes lurks in the shadows of the bushes against her house. I used the SL6 to light up her driveway and the bushes . The SL6 beam rips through the vegitation out to 75' with ease...I mean you could see squirel marks on the ground, and pine needles in the bushes 50' away no problem.
Both lights are excellent for output and beam. I like the switch on the Surge much better...as much as I like the SL6, it is a tad awkward and bulky...both lights do fit in a winter coat pocket, I have even put the SL6 in my back pants pocket to conceal it from my wife so she doesn't know how many lights I am taking for my "walk". Hope this ramble was illuminating....
