The UWLD lights are nice, but dollar per dollar, you can get more burn time and similar light output with other brands. Light Monkey is also very nice, but same story.
I think this Deep6 light is using an emitter similar to the Dive Rite LX20, and it uses 4 of them vs 1 for the Dive Rite. The can looks interesting to me, like it has a cap on both ends, vs. being 1 single piece of Delrin for the body and one for the cap. It has a nice recessed switch, and the gopro mount is nifty. The braided cover on the cable is trendy now. If they saved by using sub par batteries, you can always replace the pack for probably $150 later on, which would make this a $650 light without any ongoing support from the manufacturer--though when your cord runs out, I bet any mfg can replace it for you.
If you buy a UWLD, Light Monkey or Dive Rite, it doesn't guarantee they'll fix any issue for free for forever, but they all have historically been overly generous when it comes to warranty service and repairs. But, the cheapest you could go is the HP50 can light for $1100 or so, which is the same as buying nearly 2 of this Deep6 lights--or buying one now, and another one in a few years. And in 5 years, the technology might be so different that the ongoing support doesn't matter to you, and you buy a new one.
I'm kind of in that boat: I have a lightmonkey 12 watt LED, the first mainstream LED, that still works great, sitting in my spares box. I have a handful of BX1 lights, then I switched to BX2 when those came out. I got an HP50, then I got an EX35, and then I got an LX20, and whenever a new one comes out, I'll probably buy that one too. They all still work, but the newer lights are brighter, longer burn time, smaller, and as much as I want to use the old 12w LED again for old times sake, I still haven't used it in 4 years.
If you don't need all that light output, and you want to stick to main brands, both Light Monkey and Dive Rite have handheld lights for $500-$600. The Light Monkey appears to have built in batteries, the Dive Rite uses 18650s which you can swap out between dives, or replace in the future if they show their age. Pros and cons.
