@stuartv did you end up getting this light and how did it compare to the dgx 600?
Wow. That seems SO long ago.
IIRC, that is the light that I lost soon after I got it. I had tied a bolt snap to it in the standard way, using cave line. A sharp edge in the lanyard hole on the light cut through that line and I came up from a dive down in NC with the bolt snap still clipped to me but the light gone.
I got very little use out of it before I lost it.
Since then, though, I moved on to a light that I think is better. The Xtar D26 Whale. A bit more expensive than that SecurityING light was. But, the D26 uses one 26650 battery, instead of an 18650, so it has a fair bit more burn time. And uses the same LED emitter, so about the same brightness.
Most recently, Xtar came out with a newer version, the D26 1600. I got one of those, too, but the jury is still out. It is quite a bit brighter (thanks to a Cree XHP35 LED emitter) and has a tighter beam. But, mine was from early production and has 2 electronics issues. I have been in contact with Xtar about it. They know about the issues and have supposedly fixed them. They have told me they are sending me a replacement light with their updated construction and electronics. It is supposed to arrive next week. If the 2 issues are fixed, it will be a fantastic cordless diving light. Certainly, the best that I know of in the price range of less than $200 - 300. And it is actually less than $100.