Kudos, Selfbuilt, for this great review ~ Thanks, mate!
I purchased my first Zebralight SC600 back in November of 2011 and have since bought and carried the Mk II L2 cool white and neutral Mk II L2 in addition to my present day Mk III cool white, such as the one in Selfbuilt's excellent review.
What I can state unequivocally based upon my experience of more than 4 years of daily use is that this platform, the SC600, is one of the best, most dependable single celled 18650 LED flashlights on the market today. Regardless of which version I have used they have each performed flawlessly, day in and day out, month after month. My original SC600 works as well today as it did the very first day it was called into service nearly 4 and a half years ago.
It seems like only yesterday that I was blown away by the 750 lumens of that first SC600. And now we're talking about the Mk III which nearly doubles that output while shrinking a half inch in length and shedding more than a half ounce in weight. I call that simply amazing!
So, again, thank you for this excellent review of what I personally know to be a really great flashlight! I can't help but wonder what the future holds for the possibility of a Mk IV? Do I dare to dream!